To address the shortcomings of the traditional current and average current methods in evaluating the balance degree of beam pumping units, such as susceptibility to disturbances from operating conditions and power supply quality, and poor fault tolerance, a novel balance degree diagnosis method based on the area under the current-displacement curve was proposed. This method optimizes equipment energy consumption, efficiency, and service life by accurately assessing balance states. The upper dead center of each stroke was identified using the local extreme values of displacement data, thereby delineating the upstroke and downstroke intervals. Simpson’s rule was employed to calculate the areas under the current-displacement curves for both strokes. The balance degree was then defined by the ratio of the downstroke area to the upstroke area. Specifically, a ratio less than 0.8 indicates underbalance, 0.8~1.2 indicates balance, and greater than 1.2 indicates overbalance. A multi-method integration strategy was used for comprehensive balance state judgment. The area method achieves a diagnostic accuracy of 93.72%, significantly outperforming other methods. Based on the statistical distribution of balance degree calculation results, thresholds for extremely unbalanced states are set at 0.4 and 1.6, dividing the balance state into five levels: extremely underbalanced, underbalanced, balanced, overbalanced, and extremely overbalanced. This classification provides a robust basis for optimizing equipment operating conditions. Units in extremely unbalanced states exhibit poor working conditions and abnormal energy consumption, necessitating shutdown for maintenance and rebalancing. The area method’s high sensitivity and pronounced characterization of unbalanced states effectively enhance the recognition rate and diagnostic accuracy of unbalanced faults in beam pumping units.