To achieve real-time detection with adjustable exposure interval in ultrafast events, a triple-wedge crystal pulse splitting method with continuously adjustable pulse interval is proposed for obtaining collinear propagated sub-pulses. The generated sub-pulses have the characteristics of equal energy and high similarity. Moreover the compact structure of the triple-wedge crystal makes it easier to be embed into the optical system. The accurate relationship between the pulse interval and the structural angle，dimension and moving distance of the birefringent crystal is mathematically derived. A linear relationship exists between the pulse interval and the moving distance of the crystal at a given structural angle and crystal size. The impacts of error terms and dispersion on the pulse interval are theoretically analyzed. The feasibility of the proposed method is confirmed by mathematical analyzation and experimental results. The results will provide a reference knowledge base for multi-pulse splitting.