Totally-closed agricultural vehicle cab

The utility model belongs to the field of agricultural vehicle cabs, and particularly relates to a totally-closed agricultural vehicle cab, which comprises a left side coaming assembly, a right side coaming assembly, a rear coaming assembly and a top cover assembly, and the left side coaming assembly and the right side coaming assembly are both connected with the rear coaming assembly. The top of the left side coaming assembly and the top of the right side coaming assembly are connected with a top front cross beam, the left side coaming assembly comprises a left column A, a left column B, a left upper door frame, a left lower door frame, a left side coaming outer plate and a left side coaming inner plate, the left column A comprises an A column upper inner plate and an A column lower inner plate, and the section of the left column A is of an n-shaped structure. The three-way plate on the left side is connected with the top front cross beam and the left side wall inner plate, a double-cavity structure is forme