Self-calibration method and system for available power of excavator and engine

The invention relates to an excavator and aims to solve the problem of inaccurate set power of a main pump of an existing excavator. The invention provides an excavator and engine available power self-calibration method and system, and the method comprises the steps: a controller controls an engine to operate at each accelerator gear, and carries out the pressure building control of a hydraulic system in the operation process of each accelerator gear; gradually increasing the displacement of the main pump from a preset value to control the current to increase the displacement of the main pump until the engine is decelerated to the allowable minimum rotating speed of the gear; and calculating and calibrating the available power of each gear of the engine according to the main pump pressure, the main pump rotating speed and the main pump displacement control current when the engine of each gear is decelerated to the allowable minimum rotating speed. According to the method, the available power of each gear of t