Therefore, we developed a magnetic spinel as acid solid catalyst supporter to replace homogeneous catalyst in order to simplify the overall process. In the first step, esterification of FFAs content in cooking oil was conducted using the self-made solid acid catalyst, which has similar catalytic ability to that of sulfuric acid, and is also much easier for separation. In addition, the residual lipid can be easily transesterified without any pre-treatment. The self-made spinel-supported catalyst could be regenerated by simple calcination.