Provided a vehicle-mounted folding seat based on an omni-directional mobile platform. The vehicle-mounted folding seat based on the omni-directional mobile platform comprises a base, a folding seat assembly and a handrail control assembly, wherein the folding seat assembly and the handrail control assembly are mounted on the base; the base is arranged on a base plate of the omni-directional mobile platform and has the horizontal rotational degree of freedom relative to the omni-directional mobile platform; an electromagnetic clutch is connected between the base and the base plate of the omni-directional mobile platform. The folding seat assembly comprises two invariable-length supporting legs, two folding supporting legs, a seat plate and a backrest plate, wherein the invariable-length supporting legs and the folding supporting legs are arranged between the seat plate and the base in a mutually crossed mode; the backrest plate is located on the rear side of the seat plate; sliding rails are mounted on the two side edges of the backrest plate and provided with sliding groove rods; the lower ends of the sliding groove rods are hinged to the base; the backrest plate is connected with the sliding groove rods through the sliding rails in a sliding mode. The handrail control assembly comprises a handrail supporting rod and a handrail mounted at the top end of the handrail supporting rod; the bottom end of the handrail supporting rod is hinged to the base, and the angle between the handrail supporting rod and the base can be adjusted through stretching and retracting actions of an electric push rod.