The invention aims at providing a testing device for the puncture strength of a packaging box. An emptying board with side boards is arranged to contain the packaging box. The height of the emptying board can be adjusted through a push-up air cylinder. First hanging rings and second hanging rings are arranged through the arrangement of a top plate. The first hanging rings are used for being provided with a longitudinal first pyramid for vertical fall puncture. The second hanging rings are used for being provided with a transverse second pyramid for transverse puncture. Height observation columns are arranged for height observation to calculate work done in the puncture process of the first pyramid and the second pyramid, and then the puncture strength is judged. A spray pipe is further arranged below the top to spray water to the box, and the puncture strength generated after water is sprayed to the box is tested. The testing device is simple in structure, easy to operate and suitable for production, and the puncture strength of the packaging box can be efficiently and quickly tested.