Constant-pressure injection pile-up valve for down-hole non-block production

The invention discloses an underground integrated injection valve with absolute open constant production pressure, comprising an upper contact, a lower contact and an absolute open production valve communicated with the upper contact. The lower end of the absolute open production valve is coaxially provided with the injection valve with constant pressure communicated with the lower contact. The injection valve with constant pressure comprises a bridge channel. The both inner sides of the bridge channel are symmetrically connected with a valve handle mechanism to form the sealed valve handle mechanism. The lower contact, the injection valve with constant pressure, the absolute open production valve and the upper contact are respectively provided with a communicated flow channel. The flow channel is communicated with a through hole which is arranged on the bridge channel and is communicated with the inside and the outside. The integrated injection valve adopts metal-to-metal sealing andhas no non-metal sealing elements. So seal ability is good and reliable. Leakage loss caused by flushing fluid can be prevented during the process of flushing. The integrated injection valve is provided with the injection channel with constant pressure for blockage relieving agent, so when blockage is relieved, construction can be carried out without pipes moved.