The injection valve comprises a central pipe, and the upper end and the lower end of the central pipe are connected with an upper connector and a lower connector respectively. The outer wall surface of the central pipe is sleeved with a piston sleeve; a hydraulic cylinder barrel is coaxially arranged on the outer side of the center pipe, the upper end of the hydraulic cylinder barrel is fixedly connected with the outer wall of the upper connector, and the lower end of the hydraulic cylinder barrel is fixed to the outer wall of the piston sleeve through shear pins. An annular containing space is formed between the center pipe and the hydraulic cylinder barrel, and a liquid inlet hole is formed in the position, corresponding to the annular containing space, of the pipe wall of the center pipe. An annular groove is formed in the inner wall face of the piston sleeve, a locking ring is arranged in the annular groove, and a plurality of first sawtooth-shaped gear rings are annularly arrangedon the inner wall face, facing the center pipe, of the locking ring in the circumferential direction of the locking ring. A plurality of second sawtooth-shaped gear rings which are matched with the first sawtooth-shaped gear rings and prevent the locking rings from moving upwards are annularly arranged on the outer wall face of the center pipe and located below the piston sleeve in the circumferential direction of the center pipe. According to the utility model, fluid viscosity loss can be reduced, injected liquid is prevented from impacting the sleeve, and on-site requirements are met.