The invention provides a preparation method of novel polyurethane-modified organic silica gel. The novel polyurethane-modified organic silica gel is a segmented copolymer comprising polyurethane chain segments, polyether chain segments and organic silicon chain segments. Through introduction of the polyurethane chain segments, the novel polyurethane-modified organic silica gel retains excellent weatherability, electric insulativity, hear resistance, stain resistance, gloss and color retention, vibratrion impact resistance, adhesiveness, solvent resistance, flexibility, chemical corrosion resistance and water resistance, and short curing time, and the adhesion between the novel polyurethane-modified organic silica gel and terylene or polyester/cotton fabric is effectively improved. Throughintroduction of an amino active group-containing cross-linking agent, the novel polyurethane-modified organic silica gel has the advantages of excellent gloss retention, cohesiveness, electric insulativity and hear resistance, high surface hardness, good bending resistance, fast curing speed, good tearing resistance and no efflorescence. The novel polyurethane-modified organic silica gel as a segmented copolymer has a controllable structure, greatly develops polyurethane-modified silica gel performances and widens a polyurethane-modified silica gel application scope.