The invention discloses an organosilicon separating gel, its preparation method and application. The silicone separating gel is made of the following components in parts by weight: 54-82 parts of organopolysiloxane; 4-15 parts of hydroxyl silicone oil; 10- 25 parts; 1-6 parts of silane coupling agent. The preparation method of the organosilicon separating gel is to mix the components uniformly, heat up to 60-116°C, stir and keep warm for 5-12 hours, and then vacuumize at 120-180°C for 1-6 hours to obtain the organosilicon separating gel. glue. The application of the organosilicon separating gel is to prepare a rapid blood collection tube with serum separating gel. The organosilicon separating gel provided by the invention is hygienic, safe, non-toxic, strong in isolation, good in liquid sealing, and has superior thixotropic performance. The invention provides a method for preparing organic silicon separating gel, which has simple process, mild and controllable preparation conditions, and is easy to popularize.