The invention relates to a composite gel polymer Li-ion battery and its producing method. The Li-ion battery cell includes a three-layer composite layer of positive electrode current collector, positive electrode active material and gel polymer electrolyte obtained by a two-layer one-step coating process; a two-layer composite layer of negative electrode current collector and negative electrode active material obtained by a single-layer coating process or a negative electrode two-layer composite layer coated with a little polyurethane adhesive(s) on the surface. The gel polymer Li-ion battery cell is obtained by laminating the resultant two composite layers. The gel polymer Li-ion battery cell has a small thickness and a compact structure, and is laminated closely and easy for preparation and industrial automatic production. The Li battery prepared by the method has a uniform structure, a low internal resistance, a high uniformity, a good unity, and a high safety.