The invention discloses a real-time measuring method for a parameter curve track servo contour error. The method comprises the steps of reading the actual position of each servo shaft through a controller; performing classification determining on the servo contour error according to a relation among a current instruction position which corresponds with a current instruction position, a previous time foot point parameter, the tangent vector of each position and a distance vector; defining a nonlinear verticality function, and determining a settlement interval of the verticality function according to a contour error classification condition by means of an interval end point searching method; calculating the solution of the verticality function through a nonlinear number settlement method, thereby calculating an accurate value of the contour error. The real-time measuring method has advantages of realizing real-time tracking and accurate limiting to a servo contour error solution range, realizing high calculating precision and realizing real-time high-precision measurement for the servo contour error. The real-time measuring method can be applied to the aspects such as online processoptimization, error compensation control and equipment state monitoring in a complicated and high-speed production process, thereby improving production precision and efficiency.