The invention discloses a polyolefin photovoltaic membrane high in peel strength retention rate. The polyolefin photovoltaic membrane is prepared from, by weight parts, 100 parts of polyolefin resin a, 5-30 parts of modified polyolefin, 0.3-1.5 parts of organic peroxide initiator, 0.4-1.5 parts of crosslinking accelerator, 0.1-1.0 part of tackifier, 0.1-0.5 part of light stabilizer and 0.1-0.5 part of ultraviolet absorption agent. By adding modified polyolefin, the shortcomings that the compatibility between an addition agent and a polyolefin non-polar base material is not good and an adhesive membrane loses efficacy due to migration and diffusion are overcome, the peel strength retention rate of the polyolefin photovoltaic membrane is improved, and thus the stable adhesion performance of the polyolefin photovoltaic membrane is improved.