The invention relates to a flowerpot fixing device, which is used for fixing a flowerpot body (2) to a balcony (1). The flowerpot fixing device comprises a fixed connecting device (3), wherein the fixed connecting device (3) is installed in the balcony (1), a hollow cavity (30) is formed in the fixed connecting device (3), two deformable connecting arms (21) which are symmetrically distributed from left to right are integrally arranged on the bottom surface of the flowerpot body (2), the two deformable connecting arms (21) are used for being inserted into the hollow cavity (30) of the fixed connecting device (3) through elastic deformation, and the deformable connecting arms (21) comprise main bodies (22) which are connected with the flowerpot body (2), deformable parts (23) which are connected with the main bodies (22) and tail end guide parts (24) which are connected with the deformable parts (23).