Low-pressure heater drainage pump outlet control valve control method and system and storage medium

The invention relates to a low-pressure heater drainage pump outlet control valve control method and system and a storage medium. The method comprises the following steps that S1, an opening degree increasing instruction is sent to a low-pressure heater drainage pump outlet control valve; s2, the liquid level height in the low-pressure heater is obtained in response to completion of execution of the opening degree increasing instruction, if the current liquid level height is lower than the liquid level height obtained last time, the step S3 is executed, and if the current liquid level height is higher than the liquid level height obtained last time, the step S4 is executed; and S3, sending a working frequency reduction instruction to the drainage pump of the low-pressure heater, responding to the execution of the working frequency reduction instruction, obtaining the liquid level height in the low-pressure heater, if the current liquid level height reaches a preset value, executing the step S1, and otherwise,