Catalytic conversion method for prodn. of low carbon olefine

Hydrocarbon conversion method for producing light olefins, the feedstock is petroleum fractions of different boiling ranges, residual oil or crude oil, using solid acid catalyst in a fluidized bed reactor or moving bed catalytic conversion reaction, a temperature of 500-650 ℃, pressure of 1.5-3 × 105Pa, 0.2 to 20 hours -1 WHSV, catalyst to oil ratio of 2-12, after the reaction the catalyst regenerated by burning reactor provided with return cycle. Compared to conventional thermal cracking and steam cracking process, the process can get more total yield of propylene and butylene, propylene and butylene can reach 40%.