A precise focusing technology for a spliced TDICCD camera was introduced. Firstly, the components of focal plane were assembled to the designed locations on the camera under the circumstance of a constant temperature and vibration-isolation. Then, the Modulation Transfer Function(MTF) of the camera image was obtained through a data acquisition and processing system, the curve of MTF-focus value of every TDICCD image was plotted, and the optimum imaging plane of every TDICCD was obtained. Finally, the common optimum imaging plane of the 8 chips for TDICCD was fitted according to the every single optimum imaging plane obtained above, and then the machining values of the external interfaces of the focal plane components were derived to finish the assembly and adjustment. Precision analysis on the focusing shows that the focusing error is 9.1 μm and the relative error to the depth of field is 4.4%. The MTF test indicates that the 8 chips of TDICCD have approximately even MTF values, which are high than the camera′s static MTF requirement of 0.2. Obtained results coincide with the variation regularity of the camera′s optical MTF values and can provide references for the precise focusing technologies of the same kinds of remote sensing cameras.