The Blake criterion, which determines the bubble jet direction above a rigid boundary, was obtained through the Kelvin impulse theory. However, the theoretical model has lower prediction accuracy under a specific parameter range. Therefore, a modified judgment criterion for the bubble jet direction was proposed by considering pressure variation inside the bubble and introducing the boundary effect. The boundary element method was used to simulate the results and verify them. Meanwhile, the prediction results of the modified model and the traditional Blake criterion were compared, and the influence of dimensionless strength parameters on the prediction results of the modified model was investigated. Results show that the modified model has higher prediction accuracy than the traditional Blake criterion. The modified theoretical model provides a valuable reference for underwater explosion, seabed geophysical exploration, and related fields.