Method for detecting leakage of trunk gas pipeline by using pressure drop rate at block valve

The invention discloses a method for detecting leakage of a trunk gas pipeline by using a pressure drop rate at a block valve. The method comprises the following steps: acquiring pressure data of the block valve at a preset time interval; when the pressure data is in a preset pressure range and monotonically decreases along with time, calculating a current value of a pressure drop rate; comparing the current value of the voltage drop rate with each voltage drop rate threshold in a predetermined voltage drop rate threshold sequence; adding a preset time interval to the counter corresponding to the voltage drop rate threshold value smaller than the current value of the voltage drop rate, clearing the counter corresponding to the voltage drop rate threshold value larger than the current value of the voltage drop rate, and circulating in sequence; and when the counter corresponding to any one pressure drop rate threshold value reaches the alarm time threshold value, the cut-off valve is controlled to be closed. A