The process of biomass gasify has the characteristics of nonlinear, large delay and strong load disturbance. For these features, a double-loop intelligent control based on gray ant combination prediction algorithm was presented. Firstly, the gray prediction algorithm was used to establish temperature model of gasifies. Secondly, considering possible disturbance, the ant algorithm was introduced to optimize the gray temperature model. The temperature sub-control system was based on the optimized gray temperature model. Finally, the variable universe fuzzy control algorithm was used in the oxygen content sub-control system. The gasify-air was controlled by the fuzzy rules in order to stabilize the temperature of gasifies, and reduce the oxygen content of the combustible gases. The validity and superiority was showed in the results of simulation and work site.