The invention discloses a temperature-resistant and salt-resistant tackifying agent used for drilling fluid and a preparation method and application of the tackifying agent. The tackifying agent is obtained through polymerization of the following components: 30-50 wt% of acrylamide, 25-35 wt% of N-vinyl pyrrolidone, 25-35 wt% of reactive 4-vinyl-1-(3-sulfopropyl) pyridinium salt monomer and sodiumchloride, and the total weight of all components is 100%. An initiating agent refers to a mixture of an oxidant, a reducing agent and 2, 2-azobis(2-amidino-propyl) dihydrochloride. The viscosity of the prepared tackifying agent solution is maintained well, the viscosity of the solution has little change after aging at high temperature, and it is indicated that the provided tackifying agent is good in temperature and salt resistance and can be used as a tackifying agent for the petroleum drilling fluid under high temperature and high salt geological conditions.