A preparation method of a gradient long-effective catalytic membrane with high-strength and anti-deposition property is provided and includes: adding a nanometal oxide catalyst into an N, N-dimethylformamide solution of polyacrylonitrile or polystyrene, uniformly mixing, performing electrostatic spinning, keeping a receiver at −190° C. to −200° C. in the electrostatic spinning process, and performing freeze drying on a precursor membrane obtained after the electrostatic spinning is finished, so as to obtain the gradient long-effective catalytic membrane. According to the method, the gradient long-effective catalytic membrane with high-strength and anti-deposition property is obtained through a one-step method which adopts an ultralow-temperature-electrostatic spinning technology and combines with nanometal, the contradictory relation between the catalytic efficiency and the membrane stability in a traditional catalytic membrane is solved, the catalytic performance of the membrane is fully played, the organic polluted wastewater can be efficiently catalytically degraded, and the service life of the catalytic membrane is prolonged.