The fact that offspring's willingness to take over family business is extremely low is a severe problem hindering Chinese family businesses' succession. This paper, based on behavioral decision-making theory and opportunity cost theory, identifies the decision-making attribute of offspring's willingness to take over the business first, then explores and verifies the intervention effects of succession planning and temporal distance on such willingness. Experimental data from 135 samples indicate: offspring's willingness to take over the business is significantly higher in the situation where parents develop a complete succession plan than in the situation where no succession plan is made; temporal distance moderates the effects of succession planning on offspring's willingness. The study is supposed to provide theoretical evidence and practical suggestions for family business to promote offspring's willingness to be the successor of family business.