Answer: There are two main aspects of preparation that should be done before on-site switching operations are carried out. (1) Ideological and spiritual preparation. When the operator fills out the operation ticket, the guardian and person in charge of duty should closely combine the actual operation, focus on possible problems that may occur during the operation and the abnormalities that may occur after the operation mode is changed, and formulate targeted measures. For example: the impact on operation when there is a defect in a certain part of the equipment; whether the operation will cause malfunction of the relay protection device; whether the output of the primary and secondary equipment will be overloaded; the impact of external climate conditions on operational safety, etc. For these situations, emergency response measures should be prepared mentally. (2) Material preparation. 1) Preparation for inspection of operator equipment and safety tools. The person in charge on duty explains the purpose, tasks, and methods of the operation to those involved in the on-site operation, and announces the operation plan. After that, the guardian should prepare the operating keys, operating rods, insulating gloves and boots, electroscope and other necessary safety tools as needed. Operators, guardians, and persons in charge of duty who go to the site should all dress safely. All equipment should be visually inspected and simply performed a performance test one by one to confirm that it is in good condition and placed together for use. 2) Review operation tickets and simulation rehearsals. The operation ticket is signed by the operator and handed over to the guardian. The two of them will check that the contents of the filled-in operation ticket are correct according to the simulated wiring diagram. The guardian signs, and then the person in charge on duty reviews and confirms the signature, indicating that he is responsible for the correctness of the operation ticket. . For complex operation projects, the duty leader or full-time safety personnel should also go to the site to guide or organize so that the operation can be implemented correctly. The operating tickets are fully prepared, the operator and guardians (including the second guardian) are safely dressed, put on, put on, cover, and hold in accordance with the regulations and check that all are qualified, and then start the rehearsal on the simulated wiring diagram board. The guardian holds the ticket and sings the votes one by one, and the operator repeats and "operates" on the simulation chart one by one to conduct a practical rehearsal. After all the projects were completed in order and no problems were found, the rehearsal ended. At this point, the preparations for the official operation are ready.