The utility model relates to a counterweight device for coil cart, which is suitable for stable transfer of cold and hot rolled steel coils in the metallurgy trade. The coil cart consists of a bearer, a cart body, wheels and a hydraulic cylinder. The structure of the coil cart is that: a counterweight is arranged on the lower part of the cart body. The counterweight is fixed onto the cart body through bolts and nuts. According to calculation, the counterweight is arranged on the tail part of the coil cart to balance a moment of overturning when the cart is working and ensure that the center of gravity of the cart is located between the front wheels and the back wheels when the cart has no load. Thus, the coil has no moment of overturning both in a zero load status and in a working status, thereby improving the service life and the working stability.