The invention provides a wheel change excavator capable of being automatically lubricated and a wheel change method thereof. The wheel change excavator comprises an excavator body, track moving mechanisms, a wheel moving mechanism, a power connecting mechanism, an auxiliary support device, an automatic lubricating device and a control system; four sets of track moving mechanisms are provided, arearranged at the bottom of the excavator body, and are connected with hydraulic cylinders I; the wheel moving mechanism is provided with a walking wheel, a bent rail and a bevel gear I; the bent rail is fixed under the excavator body; the walking wheel movably sleeves the bent rail, and is connected with a hydraulic cylinder II; the power connecting mechanism is connected with an engine of the excavator, and is provided with a rhombic two-way bevel gear; the rhombic two-way bevel gear corresponds to the bevel gear I; the auxiliary support device is arranged at the bottom of the excavator body;and the automatic lubricating device is connected to each lubricating position through a hose. The wheel change excavator is skillful and practical in wheel change form, realizes automatic lubrication, and is suitable for excavator equipment.