The invention discloses a method for performing calibration time delay error testing on a time delay calibration switch of an intelligent substation. The method comprises the following steps: performing special processing on a transmitting port SV (Sampling Value) message; after the time delay calibration switch receives the SV message, calculating a time delay value from the entrance of the message into a receiving port to the transmission of the message from another port, and filling the time delay value into a reserved field of the SV message; receiving and filtering a specific SV message by the receiving port, and locking a first bit time scale of a received first frame message; calculating a measured time delay value; solving the received SV message, and extracting a switch time delay value calibrated in the reserved field of the SV message; and calculating the difference between the measured time delay value and the calibrated time delay value. The calibrated SV time delay error of the switch can be measured conveniently, so that the performance of the switch can be evaluated, and the reliability of interpolation synchronization on the SV message received by a relay protection device can be ensured. Moreover, a parameter setting process is simple; the requirement on the knowledge level of testing personnel is lowered; and the testing efficiency is high.