This paper has reported a novel ternary system consisting of (1-x-y) BiScO3-xPbTiO3-yCaZrO3 (yCZ-BS-xPT). The phase structure, microstructure and electrical parameters of the new piezoelectric material at room temperature were studied in detail. The results showed that d33 increased significantly with the increase of CZ content. Combined with the results of phase structure, the MPB of 0.02CZ-BS-xPT is located at x = 0.615, which demonstrates optimum piezoelectric performance (d33 = 470 pC/N,kp = 52.0 %, εr = 1704). At the same time, the in-situ high-temperature electrical parameters were characterized systematically. It is worth noting that the in-situ electrical parameters are more attractive. When the temperature rises from room temperature to 300 °C, the kt and kp of 0.02CZ-BS-0.615 PT decreases by less than 7 % and the kp reaches the maximum of 60.7 % at 200 °C, and remains 49.8 % even at 300 °C. In addition, the in-situ d33 test of 0.005CZ-BS-0.63 PT showed that the d33 of the material increased from room temperature to 424 °C, reaching a maximum of 690 pC/N. From room temperature to 300 °C, the change rate is only 26 %, lower than that of the undoped BS-PT, which is 38.6 %. And the d33* reaches a maximum of 994 p.m./V at 200 °C. The improved in-situ piezoelectric properties of yCZ-BS-xPT ternary system makes it a great candidate for high temperature piezoelectric applications.