The invention relates to a determination method for a semi-rigid base bituminous pavement crack damage state. The method comprises the steps that 1, nondestructive deflection testing is conducted on the top surface of a semi-rigid base bituminous pavement crack, the portions which are 15 cm away from the two sides of the crack, the portions which are 50 cm away from the two sides of the crack, the portions which are 100 cm away from the two sides of the crack, the portions which are 150 cm away from the two sides of the rack and the portions which are 200 cm away from the two sides of the crack, and the deflection values of all the testing points are obtained; 2, a deflection curve is drawn through the distance between the testing points and the crack and the deflection values of the testing points; 3, the crack damage state is determined comprehensively according to the line shape of the deflection curve and the maximum deflection value. The determination method for the semi-rigid base bituminous pavement crack damage state has the advantages that deflection testing is conducted on a certain range of the two sides of the crack, and the range of influence of the crack and the damage state of the crack are determined accurately according to the distance from the testing points to the crack and the reflection curve which is drawn according to the deflection values. According to the determination method for the semi-rigid base bituminous pavement crack damage state, the problem that existing determination of the appearance observation of the semi-rigid base bituminous pavement crack damage state is not accurate is solved, and a scientific, accurate and economical basis can be provided for making a pavement maintenance and rehabilitation scheme.