The invention relates to a fan blade impulse load recognition method. Based on the conjugate gradient least-squares iteration algorithm, the method comprises the following steps that (1), a hammering method is adopted for measuring the frequency-response function between a position point where an impulse load is exerted on a fan blade and a response measure point of the fan blade, inverse fast fourier transformation is used for obtaining a unit impulse response function, and therefore a transfer matrix is obtained through deconvolution; (2), an acceleration sensor is used for measuring acceleration response signals generated by the impulse load which acts on the fan blade; (3), the number of iterations, loads to be recognized, response residuals and iteration searching directions of the conjugate gradient least-squares iteration algorithm are initialized; (4), the number of iterations, loads to be recognized, response residuals, the conjugate gradient coefficients and the iteration searching directions under the current number of iterations are updated; (5) whether a heuristic type convergence termination criterion is met is judged; (6) regularized loads to be recognized are obtained.