The invention discloses a crop straw fertilizer producing robot. The robot comprises a movable cart body, an untying doping device, a collecting pulverizing device, a material elevation device, a rubbing pulverizing device and a sewage storage stirring device, wherein the untying doping device is arranged at one end of the cart body and used for piling straw into strip shapes along the moving route of the cart body, the collecting pulverizing device is arranged at the other end of the cart body and used for collecting piled up straw, the material elevation device is used for delivering straw collected by the collecting pulverizing device into the rubbing pulverizing device, the rubbing pulverizing device is arranged on the cart body and used for rubbing and pulverizing the straw, the strawis rubbed and pulverized and fall off from the cart body to be piled up on the ground, and the sewage storage stirring device is arranged on the cart body to be used for storing sewage.