There is a developing trend of wide field of view and high resolution for the remote sensor, and the imaging focal plane is longer and longer. TDICCD has been widely used in the field of the remote sensor with its good imaging performance, and it is more and more important to achieve large focal plane for TDICCD assembly. The conventional optical assembly length is limited by glass material and glass glue, moreover it introduces chromatic aberration, and the directive assembly will descend the imaging quality. A new assembly method called mechanical interleaving assembly of TDICCD focal plane, which eliminates the above defects, is put forward. Using mechanical tangent-screws adjusting method, the assembly of two TDICCDs staggerd in space is finished on the apparatus which is composed of a long work-distance magnifying microscope, a fine collimating reticle, a negative-pressure adsorption air float guide and precision slidway. The assembly focal plane length reaches 400 mm and the measuring error is not greater than 2.9 μm. The relationship of positions of TDICCDs is ensured, and the image displacement disposed method of electronic abutting joint zero clearance imaging picture is achieved.