Abstract: The operation characteristics of bulb tubular units with low water head limit the performance of primary frequency regulation to a certain extent and often result in poor performance of primary frequency regulation examination. Through the theoretical analysis and simulation of the control logic of the primary frequency modulation of bulb tubular unit, this paper studies the influential factors of the regulation rate and depth and their solutions under the premise of ensuring safe and stable operation of the unit and meeting the requirements of the power grid assessment index. The real machine test show that the performance of primary frequency regulation of the unit is improved, the integral quantity of electricity increase after primary frequency regulation operation, and the actual benefit is improved, which can be used for reference for optimizing the performance of primary frequency regulation of bulb tubular units.