The invention discloses a primary frequency modulation spinning reserve capacity collocation method considering hydroelectric overload capacity. The collocation method comprises the following steps of A, obtaining water head and flow information of each hydroelectric generating set; B, calculating output of each hydroelectric generating set according to the water head and flow information; C, judging the overload capacity coefficient of each hydroelectric generating set according to the output and the self rated power of the hydroelectric generating set; D, correcting the amplitude-limiting link parameter P of each generator speed regulation system according to the overload capacity coefficients; and E, determining the spinning reserve capacity in an off-line simulation link according to the minimum of spinning reserve set number or the minimum of spinning reserve total capacity based on the amplitude-limiting link parameter P of the generator speed regulation system. By adoption of the method, frequency stability can be greatly improved, and the spinning reserve collocation capacity can be dramatically reduced.