Nearly all the arcs or circles of grooves on traditional distribution valves are concentric, yet eccentric circles or arcs are found in new-style distribution valves. This paper presents calculation formulas of a new-style distribution valve in camshaft connecting-rod type low speed high torque hydraulic motors. By making mechanical studies on the distribution valve based on presented formulas, some performance curves were gotten and some issues that should be noticed were pointed out when designing this new kind of distribution valve.