Aiming at the problems of weak adaptability and poor climbing ability of oil and gas pipeline robots to oil and gas pipelines, a crawler-type oil and gas pipeline inspection robot with variable diameter was proposed. SolidWorks 3D software was used to build a prototype model, and then the prototype model was imported into ADAMS simulation software. In the software, the model was constrainted and simplified according to the actual situation, kinematics simulation of the pipeline robot was carried out to analyze its ability of variable diameter and climbing. Finally, a test platform to test and verify the climbing ability of the pipeline robot was built. The results show that the robot can adapt to oil and gas pipelines with a diameter of 400 mm to 600 mm, and climb slopes of 45° and 90° under its own weight.