The invention discloses a qualitative and quantitative analysis method for an old negative plate of a lead acid battery. The method comprises the following steps: firstly, dissecting a tested battery, taking out the negative plate, and cleaning the surface separator of the negative plate; washing the negative plate with deionized water until the surface thereof becomes neutral; further soaking the negative plate in boric acid- salicylic acid impregnation liquid for more than 20 minutes while heating, and keeping temperature of the boric acid-salicylic acid impregnation liquid to be 60-80 DEG C during the soaking process; then, taking out and baking the negative plate to completely remove water on the surface thereof; and finally, taking down a lead paste from the dried negative plate, grinding the lead paste into powder, and carrying out qualitative and quantitative analysis on constituents of the negative plate through an XRD(X-Ray Diffraction)-Rietveld method. According to the invention, firstly, the old negative plate drawn out from the battery is pretreated, a protective layer is formed on the surface of the negative plate, oxidization of lead of the negative plate is avoided effectively and residual of sulfuric acid on the surface of the negative plate is removed, as a result, the negative plate can be dried directly by a normal drying method, and the qualitative and quantitative analysis method is high in testing accuracy, convenient and simple, low-cost and pollution-free.