The utility model discloses a machine frame moving and steering mechanism of an X-ray machine with a C-shaped arm. The machine frame moving and steering mechanism comprises a front moving wheel, a rear moving wheel, a steering transmission mechanism and a steering handle. A first rear wheel connecting frame and a second rear wheel connecting frame which are inclined towards the front portion of a machine frame are arranged on two sides of the machine frame symmetrically. A first/second moving wheel is arranged at the lower portion of the first/second connecting frame through a first/second rear wheel axle. The steering transmission mechanism is formed by a chain wheel group and a chain meshed with the chain wheel group. The chain wheel group is formed by eight chains which include a first large chain wheel, a first small chain wheel, a second large chain wheel, a second small chain wheel, a third small chain wheel, a third large chain wheel, a fourth small chain wheel and a fifth small chain wheel. The first large chain wheel is connected with a steering handle in coaxial mode through a rear wheel steering linkage rod. The second large chain wheel is fixedly connected with the first rear wheel axle, and the third large chain wheel is fixedly connected with the second rear wheel axle. The machine frame moving and steering mechanism is reasonable in design, convenient to operate, flexible to steer and push, light, labor-saving and convenient to popularize and use.