By evaluating green process innovation and its innovator’s benefit including short- and long-term dimensions, we first analyzed the relationship between green process innovation and its benefits. Second, we set up a regression model to test the hypotheses using 267 survey data from coal mining firms in China. Finally, we verified the positive relationship between green process innovation and its long-term benefit, and the non-significant relationship between green process innovation and its short-term benefit, and the mediating effect played by firm image in the long run.