The invention discloses a pressure tube ablation simulating apparatus comprising a test device, a power supply and potential measuring device, a water vapor generating device, and a slide rail transmission device. The test device comprises a case body and an experimental table in the case body. A horizontal slide rail is horizontally fixed to the experimental table. Support clamps are fixed to a fixed slide block and a movable slide block on the horizontal slide rail in order to be equipped with two pressure tubes required to be tested. The water vapor generating device supplies water vapor to the case body. The slide rail transmission device controls the movable slide block to move. The power supply and potential measuring device is connected with the two pressure tubes through a first through hole, supplies power to the two pressure tubes, and records a voltage parameter in order to obtain safety distance, not generating discharge, of the two pressure tubes. The pressure tube ablation simulating apparatus solves a technical problem the distance and the potential difference between the pressure tubes are not easy to control and thus cause a high safety risk, and achieves an effect of improving the safety performance of block valve chamber of a gas pipeline.