The invention discloses a relay valve with an empty and loaded vehicle brake cylinder pressure adjusting function. The relay valve comprises a valve body assembly, wherein a supply valve, an exhaust valve, a balance piston assembly, an empty and loaded vehicle piston assembly, a top rod, a pull rod and a jumping spring are arranged in the valve body assembly. The relay valve disclosed by the invention controls an auxiliary reservoir to inflate/deflate a brake cylinder according to the pressure change of a volume chamber, so that a train is braked, pressurized and released; the relay valve has the empty and loaded vehicle brake pressure adjusting function, so that the brake cylinder pressure can be controlled according to the load weight tonnage of a vehicle, different brake cylinder pressures are supplied according to the load weights of the vehicle, and the reliability of the braking is ensured.