The present disclosure is related to a slide valve, a slide valve adjustment mechanism and a screw compressor. The slide valve includes a static slide valve and a moving slide valve, wherein the static slide valve is fixedly installed in a slide valve cavity and provided with an axially-penetrating valve hole; a plurality of bypass holes communicating with the valve hole (110) are formed in the sidewall of the static slide valve, and an exhaust port is formed in the sidewall of one end of the static slide valve. The slide valve may avoid scraping between the slide valve and a screw rotor and the slide valve cavity. Gaps between the slide valve and parts which cooperate with same are reduced, so that the leakage is reduced while the energy efficiency of the compressor is increased.