Objective This study aimed to estimate the impact of the threshold of Autocapture algorithm on the pacemaker's service life.Methods Seventy-four patients implanted with VVI pacemaker were retrospectively evaluated.Among them,48 were implanted with pacemaker of autocapture function.Diagnostic data were retrieved from device memory.Pacemaker's service life was estimated according to the working flow and voltage.Results (1) The average working voltage of the control group and the observation group was (2.8 ± 0.4) V and (1.1 ± 0.4)V respectively.The difference was statistically significant;(2) The battery life in the observation group was (12.59 ± 0.55) a,significantly longer than that in the control group (6.74 ± 1.12) a,with an 86.8％ increase of the device's estimated service life (P＜0.05).Conclusion The Autocapture function results in a significant service life of cardiac pacemaker and represents valuable clinical technology.