A second boy has been charged over a "clotheslining" trap that caused serious injuries to a motorcyclist outside the Perth train station.

It is alleged the 11-year-old boy tied the rope across Wellington Street that knocked Lawson Mills, 19, off his motorcycle last month.

It is alleged Mr Mills was also attacked with a bottle while he was on the ground.

He suffered severe burns to his throat and a cut to his head.

Police charged a 12-year-old boy from Bayswater over the attack late last month.

Last night, they charged the 11-year-old boy, from Innaloo, was charged with one count of acts or omissions causing the life, health of safety of a person to be endangered.

He is due to appear in the Perth Children's Court on February 5.