The basic situation of the coal-to-olefin project phase I of China Coal Shaanxi Yulin Energy Chemical Co., Ltd is briefly introduced in this paper. The factors affecting the high load operation of the main production units and the methods to improve the operating load are analyzed. Based on the actual production experience, the measures to extend the operation cycle are summarized and the optimal production load of the coal-to-olefin enterprises is determined. This can be a reference for similar enterprises.