A Melbourne man has denied deliberately shooting his partner in the face with a speargun and telling her: "Babe, you're going to lose an eye but I'll buy you a new one".

The man, who cannot be named for legal reasons, is standing trial in the County Court of Victoria after pleading not guilty to 24 offences allegedly committed between 2013 and 2016.

The court was also told on Wednesday that on one occasion, the man slit a chicken's throat in front of the woman and said: "Don't ever leave me or I'll do this to your family".

It's alleged that during their relationship, which the woman was too scared to leave, the man would dose the woman's coffee with the antipsychotic and sedative Seroquel.

On February 14, 2016, he allegedly gave her the drug before beating her, telling her that Valentine's Day and her birthday were the only days she would be treated like a queen.