To address the bottleneck issues of low energy conversion efficiency and single performance regulation method in existing PZT thin films, this paper focuses on the problem of insufficient piezoelectric performance of PZT thin films and investigates the effects of A-site doping with La3+ and Ba2+ on the electrical properties of PZT thin films, as well as analyzes the doping modification mechanism. Lead lanthanum zirconate titanate (PLZT) thin films and lead barium zirconate titanate (PBZT) thin films were prepared by the sol-gel spin-coating method. Furthermore, the effects of A-site co-doping of La3+ and Ba2+ on the performance regulation of PZT thin films were studied. The crystal structures and electrical properties of PLBZT thin films with different doping ratios were compared. The results show that the co-doping of La3+ and Ba2+ can synergistically improve the electrical properties of the thin films. The optimal performance is achieved with the co-doping of 2% La3+ and 2% Ba2+ (P1.06L0.02B0.02ZT). Compared with the PZT thin film, the dielectric constant ε? of the P1.06L0.02B0.02ZT thin film is 1718.3 (an increase of 75.23%), and the piezoelectric constant d?? is 244.1 pC/N (an increase of 39.65%)..