ABSTRACT Cracking is a common fault in asphalt and concrete pavements, which causes water damage and further defects if not repaired in timely fashion. Conventional pavement crack sealing methods based on machines and manual operations are generally subjective, labour-intensive, risky, and inefficient. A laboratory prototype of an automatic pavement crack sealing platform is proposed in this paper, which uses a modified three-dimensional (3D) printer and computer vision. A modified 3D printer based on fused deposition modelling (FDM) was combined with an image capturing platform, an image processing algorithm and a path planning method to form the automated pavement crack sealing platform, which can automatically detect pavement cracks and seal them with bitumen emulsion sealant. Specimens of concrete pavement slabs with cracks were produced in the laboratory to test the proposed method, and the cracks were then detected and sealed by the proposed platform. The results show that 3D printing is an effective method for automated pavement crack sealing, which is recommended in the field of automatic road maintenance and repair.