Chilean jack mackerel (Trachurus murphyi) is one of the important economic fisheries in the Southeast Pacific Ocean. The stock abundance is inherently affected by recruitment. To find out the status of recruitment is of great significance to the sustainable yield and scientific management of resources. The recruitment of Chilean jack mackerel between 1971 and 2017 is divided into different regimes based on regime test. Then, the Bayesian model averaging is applied to the relationship between recruitment and five environmental factors (sea surface temperature, sea surface salinity, sea surface height, El Niño and Pacific decadal oscillation), and the impact of regime change in recruitment forecast is also discussed. The results show that the first regime (1971−1980) is more disturbed by fishing; in the second regime (1981−1990), El Niño has the highest probability of explaining for the change of recruitment; the environmental factor with the highest explanatory probability is Pacific Decadal Oscillation in the third regime (1991−2001); in the fourth regime (2002−2015), El Niño most likely explains the change in recruitment; comparing the analysis of regime shift and no regime shift models, there is a significant difference between the two. However, the results, with different regimes, are more reasonable to explain the change of recruitment. Recruitment abundance is affected by multiple environmental factors, but in different regimes, the dominant environmental factor changes. The regime shifts of recruitment are induced by the alternation of cold and warm periods of interdecadal Pacific decadal oscillation, and El Niño. It is suggested that different regime shift and their impact factors should be considered in the future assessment and management of Chilean jack mackerel resources.