step 1: obtaining running states of a heat engine unit, and determining a first code of a corresponding device in combination with a safety measure content of a corresponding heat engine and a DCS marking state, so as to perform a matching analysis with a task condition code, and determining first heat engine devices for power-off control based on the intelligent switch cabinet and second heat engine devices based on power-on control;

step 2: determining a first allowable operation item based on the power-off control and a second allowable operation item based on the power-on control of the intelligent switch cabinet, and determining required operation items in combination with a current actual situation of elements to be operated in the intelligent switch cabinet;

step 3: setting a first work task to an electrical five-prevention system and setting a second work task to an electrical work ticket system according to heat engine devices of requiring to be controlled related to the heat engine unit, and setting an operation authority to the elements to be operated of the intelligent switch cabinet based on the required operation items after the setting is completed;

step 4: based on the operation authority of being set, performing the power-off operation on the first heat engine devices of being associated and performing the power-on operation on the second heat engine devices of being associated;

wherein the step 2 comprises:

determining the first allowable operation item corresponding to each of the first heat engine devices in the power-off control, and judging a first current code of the elements to be operated corresponding to each of the first heat engine devices, if a power-off requirement is met, keeping the first current code unchanged, otherwise, adjusting the first current code into a power-off code;

determining the second allowable operation item corresponding to each of the second heat engine devices in the power-on control, and judging a second current code of the elements to be operated corresponding to each of the second heat engine devices, if a power-on requirement is met, keeping the second current code unchanged, otherwise, adjusting the second current code to a power-on code;

obtaining position information of handcarts corresponding to each of the first heat engine devices and each of the second heat engine devices in the intelligent switch cabinet, marking the handcarts in a test position as 1 and marking the handcarts in a working position as 0;

obtaining information of load side grounding breakers corresponding to each of the first heat engine devices and each of the second heat engine devices, and recording a load side grounding breaker of being closed as 1 and recording a load side grounding breaker of being opened as 0;

determining a first item code corresponding to each of the first heat engine devices and a second item code corresponding to each of the second heat engine devices based on recording results;

comparing each operation item code with corresponding a power-off result code and a power-on result code to determine the required operation items of each of the heat engine devices.