What does Richard Emery, the hand-picked head of Mayor Bill de Blasio’s cop-watchdog Civilian Complaint Review Board, have in common with Sheldon Silver, the on-his-way-to-prison former speaker of the New York Assembly?

Rainmaking.

Silver filched millions, using his office to feloniously steer potential asbestos litigants to the trial lawyers at Weitz & Luxenberg PC. That’s one reason why he’s going to jail.

Emery clearly isn’t playing in that league, not even close. But can you be just a little bit conflicted?

He has made a good living litigating against New York City for some years, switching sides, or so it appeared, in 2014 — when de Blasio appointed him head of the CCRB as part of a professed effort to bolster trust in the NYPD.

But, of course, appearances can deceive.

Emery is a name partner in the self-described “boutique” trial-law firm of Emery Celli Brinkerhoff Abady — which, in its own words, “has successfully represented hundreds of clients in police misconduct cases against police departments throughout the Tri-State area, from high profile wrongful death cases to smaller false arrest and excessive force cases.”

Here’s where the rainmaking comes in, according to published reports.

Individuals certified as “victims” of NYPD misconduct by Emery’s review board then turn around and hire Emery’s law firm to pursue civil suits against the NYPD.

If this seems a little circular, it is.

Or, as police union president Patrick Lynch puts it: “How can the law firm of the sitting chairman of the CCRB earn money by suing the city over cases that the CCRB has substantiated against police officers? . . . [S]ubstantiating a citizen’s complaint against a police officer gives support to the civil suit. It’s an irreconcilable conflict of interest.”

Or, he might have noted, substantiating an illegitimate complaint because it represents a potentially lucrative lawsuit.

Lynch is by no means a disinterested party, of course, but common sense says he’s not wrong.

Except that he is. Officially, anyway. No kidding.

That’s because the city’s mayorally appointed Conflict of Interest Board has handed Emery Celli Brinkerhoff Abady an ethics pass: It’s OK to take (Emery-certified) CCRB cases because Emery says he’ll recuse himself in each and every one. Or something.

This is unserious on its face. For one thing, it makes no difference which lawyers litigate a particular case, because a law firm’s profits go into a single pot. For another, it’s the name on the shingle that makes the rain, and Emery’s stands out.

But it’s OK, because the five-member board — de Blasio added two campaign donors to the panel upon taking office — says it is. End of story.

This is the same conflicts board that:

Last month slapped City Council Speaker Melissa Mark-Viverito’s hand — reducing a potential $25,000 fine for improper use of campaign consultants to $7,000. (Mark-Viverito promised not to do it again.)

Has studiously avoided any involvement in the endlessly fascinating Central Park carriage-horse melodrama. It’s all about campaign donations — de Blasio’s obsession with the subject brings to mind the old saw about the honest politician being the one who stays bought — and this clearly is COIB turf. (Not that it will bite.)

Ignored a $350,000 teachers union donation to de Blasio’s super PAC the same month that the mayor laid a $9 billion contract settlement on the — what else? — teachers union. (Hey, if you want to play, you gotta pay, right?)

Came down like thunder on two city sanitation workers for taking $10 “bribes” — fining each $2,000 and forcing one to retire. (Really, a board has to flex its muscles every now and then; it’s a matter of self-respect.)

Obviously, the conflicts board is hopeless — and has been for some time. Politics is politics, and didn’t Mike Bloomberg and Christine Quinn engineer themselves a pass on term limits?

But the Emery ethics lapse is a slightly different story.

De Blasio has been at daggers’ points with the cops since before he took office — shamefully accusing them of racism during that high-voltage stop-and-frisk dispute and driving NYPD rank-and-file to near-mutiny with his ham-handed response to the death of Eric Garner.

The last thing the mayor needs — the last thing New York City needs — is for the cops to conclude that the head of the CCRB is playing litigation lotto with their careers. Indeed, with their lives.

But this happens to be a fact, and de Blasio needs to put an end to it.