The classical newsvendor model assumes that the decision maker is risk-neutral. Since the decision maker’s actual order behavior is affected by risk preference, there is one deviation between the actual order quantity and the expected profit-maximizing order quantity. Based on the constant absolute risk aversion(CARA) utility function, the formation mechanism of newsvendor decision bias is explained from the perspective of risk preference. The results of behavioral experiments show that the decision maker’s risk preference will reverse with the relative cost increase. The decision maker exhibits the risk aversion(love) order behavior under the high(low)-profit market. Furthermore, risk aversion has more significant effect on the decision maker’s order behavior. The newsvendor decision bias reveals that in the actual inventory management, considering the decision maker’s individual risk preference is beneficial to diminish the deviation between the theory model and the practical situation, so as to improve the inventory management efficiency.