The invention provides a determination method of the bearing capacity of an overlong bored pile. The method comprises the following steps that the total stiffness of pile soil is determined, and a standard value of the frictional resistance of the pile side of each layer of pile soil and a standard value of the counterforce of the pile bottom are determined in accordance with engineering needs; a mathematically traditional fitting method is utilized to determine a hyperbolic function passing parameter of the pile side of each layer of the pile soil and determine a hyperbolic function passing parameter of the pile bottom of each layer of the pile soil; a length measuring device is utilized to determine the pile diameter D; the subsection length of a pile body is determined in accordance with the requirement of calculation accuracy, and each subsection corresponds to one layer of the pile soil; the frictional resistance of the pile side on the subsection length of each pile body is calculated one by one, and a control value of the frictional resistance of the pile side is determined; and whether a control value of the counterforce of the pile bottom and the vertical bearing capacity of a pile foundation meet the conditions or not is determined, thereby determining the bearing capacity of the overlong bored pile. By using the determination method of the bearing capacity of the overlong bored pile, the defects in aspects of bearing property analysis and parameter selection calculation of the overlong bored pile in the prior art can be overcome.