The invention discloses an elastic detection device of large hook spring which comprises a bottom plate, wherein the bottom plate is fixed on the ground through bolts, the bracket is fixedly connectedon two sides of the bottom plate, the cross beam is fixedly connected above the bracket, the guide rod is fixed in the middle of the bottom plate for guiding the spring, the pressure sensor is arranged in the bottom plate, the hydraulic cylinder is connected with an ear seat on the cross beam and the pressing plate through a pin, the pressure plate slides up and down in the guide groove at the inner side of the bracket under the pushing and pulling effect of the hydraulic cylinder to realize the compression and the release of the spring, the device has the advantages of simple structure, safety and reliability, small occupied area, wide detection range, high degree of automation, smooth, accurate and easy control of hydraulic control application load, It can realize the testing of insideand outside spring elastic force of the large hook serials. The deformation of spring can be directly observed by applying a given load to the spring. Not only is it the verification of design performance, but also it is a kind of inspection for the purchased springs.