To reduce the work of assembling corrugated boxes for online commerce and packing the contents of the boxes, while enhancing convenience of disposal and separation for consumers, a new lock structure has been developed featuring the following: ① The lid can be locked when the end of the flap is inserted, eliminating the necessity of closing it with tape, and the flap incorrectly opening by itself. ②The assembly procedure is the same as before, but the assembly time can be reduced to one third without using sealing tape. ③ There is no change in the amount of materials used.