There were two chemical reactions in the production of biodiesel by two-step chemical method,one was the esterfication of free fatty acid and the other was the transesterification of neutral oil.In the actual production process,the glass-line reactor was usually used,so the srirring intensity was low.In addition,the water produced by the esterification of free fatty acid made the esterification reaction perform to the reserse direction.The above two points affected the esterifcation rate.Therefore,the improvement measures were taken,such as adding continuous adsorption dehydration column in the return piping of methanol to remove the generated water,and setting up compulsory crosslinking machine outside the reactor to increase the contact of reactants to improve esterification rate.The practice showed that after improvement,methanol dosage was decreased,reaction time was reduced and esterification rate was improved,which effectively reduced production costs of company.