The invention discloses an electric vehicle battery thermal management system employing a porous material. The electric vehicle battery thermal management system comprises a power battery pack battery box and an air processing system, wherein the power battery pack battery box comprises a battery box body and battery units, the battery units are arranged in the battery box body an in array way, the air processing system is a hot pump type refrigerating system, comprises an indoor machine part and an outdoor machine part and is used for purifying, cooling/heating circulation air, at least one porous material plate is arranged in the battery box body and is arranged along a radial direction of the battery units, opening holes are formed in the porous material plate and are larger than the sizes of end surfaces of the battery units, the battery units are inserted into the opening holes of the porous material plate, and contact parts of the battery units and the porous material plates are filled with thermal conductive plastic. By the electric vehicle battery thermal management system, a power battery pack can be enabled to run within an optimal temperature range, a huge impact force generated by accident collision of an electric vehicle can be effectively reduced, and the working efficiency, the safety and the reliability of the power battery pack are comprehensively improved.