A new method has been developed to address the challenging issues of complex and low-accuracy reserve estimation for condensate gas reservoirs. An analysis was conducted on the commonly used Eaton-Jacoby empirical formula for predicting condensate oil recovery which revealed its poor applicability to gas reservoirs with low condensate content, large formation saturation pressure difference, and high abandonment pressure. Based on the fluid phase behavior of condensate gas reservoirs, a new method was proposed to determine recovery by integrating material balance method and PVT experiments method. The material balance method calculates the recovery when reservoir pressure decreases to dew point pressure, while the PVT experiments method calculates the recovery when dew point pressure decreases to abandonment pressure. The sum of the recoveries from these two stages gives the final recovery. Two condensate gas reservoirs with numerical simulation models were selected, and the results from the new method were compared to the numerical simulation predictions. The results showed that the new method yielded similar results to the numerical simulation predictions, proving its applicability. The new method is simple to implement, particularly suitable for closed gas reservoirs, and provides a new approach for calculating the recoverable reserves of condensate oil.