The invention discloses a detection method for track geometric irregularity based on a two-dimensional laser displacement sensor. A left laser sensor, a right laser sensor, a longitudinal inclinometer, a lateral inclination meter, a gyroscope, a lateral accelerometer, and a left vertical acceleration are installed on the detection beam. meter, right vertical accelerometer, the left laser sensor and the right laser sensor are two-dimensional laser sensors; perform the following measurements: track gauge detection, height detection, rail direction detection, horizontal superhigh detection, twist detection, curvature detection, Rail vertical as well as side wear measurements. The present invention adopts a high-speed two-dimensional laser displacement sensor, which has strong anti-interference ability. Based on the two-dimensional sensor, there is no complicated image processing step, and with simple and effective back-end algorithm processing, it has higher detection and calculation speed. It can effectively eliminate the influence of vehicle body vibration on the detection result, the detection result has high repeatability, can compensate the detection result, and has higher detection accuracy.