A railway vehicle, a coupler, and a coupler body thereof. The coupler body comprises an upper traction platform, a lower traction platform, a lock chamber, and a pin hole. A traction surface of an upper traction platform and/or a lower traction platform is divided into a contact area and a yielding area along the direction approaching the lock chamber, an extension face of the end of the contact area close to the lock chamber is an M2 face, and the yielding area is positioned at the side of the M2 face close to the pin hole. The yielding area is positioned on the side of the contact area next to the lock chamber and there is a gap and no contact between the yielding area and a traction platform of a coupler knuckle.