Abstract: The mechanism of non-hydrogen mild cracking with molecular sieve and the molecular sieve test device are introduced. With this device, a pour point depression test on Hainan waxy crude oil has been carried out. The test results has shown that by the treatment of molecular sieve, the light fraction of crude oil is obviously increased, the pour point is decreased from 20℃ to -10.5℃, and other properties of crude oil are effectively improved.