Organic silicone adhesives can be classified according to molecular structure, curing method, curing temperature, etc., as follows:

- **By molecular structure**:
It can be divided into two categories: organic silicone resin adhesives and organic silicone rubber adhesives. Silicone resin is composed of a spatial network structure with si-o-si as the main chain. It is a cross-linked semi-inorganic polymer with organic groups connected to silicon atoms. It can be further condensed into a highly cross-linked, hard and brittle resin at high temperature. Silicone rubber is a linear elastomer with a relatively high molecular weight (molecular weight ranging from tens of thousands to hundreds of thousands) with si-o-si as the main chain. It forms an elastomer with several cross-linking points under the action of curing agents and catalysts. Silicone rubber mainly composed of polydimethylsiloxane is also called silicone glue. The former is mainly used for bonding metals and heat-resistant non-metallic materials, and the resulting bonded parts can be used in the temperature range of -60 to 250°C; the latter is mainly used for bonding heat-resistant rubber, rubber and metal and other non-metallic materials, and can generally be used at -60 to 200°C.

- **According to the curing method**:
It can be divided into three categories: condensation type, addition type and polymerization type. Among them, the addition type is a silicone adhesive made with cyanide-containing polysiloxane and vinyl polysiloxane as the main materials under the action of a catalyst.

- **According to the curing temperature**:
It can be divided into three categories: high temperature curing, low temperature curing and room temperature curing. Silicone adhesives have excellent high and low temperature resistance, water resistance, corrosion resistance, atmospheric aging resistance and other characteristics. They can be mixed with silicone resin solution or silicone rubber, fillers, cross-linking agents, catalysts and other additives. They are suitable for bonding and sealing of metal, ceramics, glass and plastic parts. They are widely used in aerospace, aviation, electronics, construction and medical and health departments.

In addition, silicone adhesives can be roughly divided into pure silicone adhesives and modified silicone adhesives. Pure silicone adhesives are mainly composed of active polysiloxanes (hydroxyl-terminated silicone rubber, hydrogen-containing or vinyl silicone oil), curing agents, catalysts, fillers and additives. According to the difference in curing reaction, it can be divided into condensation type, free radical initiation type and hydrosilylation type; according to the different composition and function, it can also be divided into single-component silicone, two-component silicone and silicone pressure-sensitive adhesive.