The invention relates to a method for measuring the initial distortion of concrete and relative device. Wherein, it comprises the detections on the condensation of concrete and the self-dry contraction after initial condensation, while the front one uses vertical length measure, while embedding temperature sensor in the concrete, arranges detector at the top, and uses non-contact displacement sensor to measure the detector displacement generated by the concrete condensation, and uses computer to record the initial data of displacement sensor and the temperature sensor and the period data until the concrete is condensate; the second one uses transverse length measure method that embedding temperature sensor into the concrete; arranges detectors at two ends of test sample; uses non-contact displacement sensor to measure the displaces of detectors caused by the self-dry contraction after the condensation; and uses computer to record the initial data of displacement sensor and the temperature sensor and the period data. The invention can make the measure initial time of self contraction after irrigate molding, while the test result has better repeat ability and high accuracy.