The invention provides a driving brake and parking brake integrated wet type brake with an adjustable separation gap, and belongs to the technical field of vehicle brake. The problems that the requirement of vehicle speed increasing for the property of a brake is higher and higher, the size is large, the function is single, multiple brake friction sheets are not prone to separating, and a dry typebrake is high in temperature rise are solved. The brake comprises a rear shell, a middle shell, an end cover, a guide column, a return spring, a baffle, a disc spring, a gasket, an adjusting bolt, aninner tooth friction plate, an outer tooth friction plate, a parking brake piston, an input gear shaft, a pressing plate and a driving brake piston. Functions of driving brake, parking brake, friction pair forced separating, friction pair separation gap adjusting, parking emergency relief and the like can be achieved. The driving brake piston and the parking brake piston are arranged on one part,the size of the brake is reduced, the brake life of the brake is prolonged, the braking torque stability is kept, and reliability is improved.