Abstract: 4130X steel is the main material of compressed natural gas high-pressure gas cylinders. In order to obtain the damage evolution law under load, digital image correlation technology (DIC) and acoustic emission technology are combined to monitor the tensile fracture damage state of 4130X steel. The surface strain standard deviation (SD) of the tensile specimen was used to characterize the damage evolution law, and combined with the experience analysis of the acoustic emission signal characteristic parameters of the damage process, the acoustic micro-damage, plastic damage, and crack growth of 4130X steel were obtained. The distribution of the intensity of the transmitted signal. The test results show that the analysis method combining DIC and acoustic emission technology can obtain the damage evolution law of 4130X steel during tensile fracture process, which can provide a reference for the damage state monitoring in service state.