The invention relates to a silane coupling agent for modifying clay, modified clay, low-heat-generation rubber and a preparation method. The structure of the silane coupling agent is shown in the description. The low-heat-generation rubber is prepared from the following raw materials in parts by weight: 80 to 120 parts of raw rubber, 40 to 80 parts of reinforcing agent, 6 to 10 parts of active agent, 2 to 5 parts of anti-aging agent, 1.5 to 2 parts of vulcanizing agent and 0.5 to 2 parts of accelerant, wherein the reinforcing agent is a mixture of carbon black and modified clay, and the ratioof the carbon black to the modified clay is 1:1-1.8:1. According to the invention, the dispersibility of the clay and the carbon black in the rubber can be effectively improved, the optimal dosage ratio of the clay can be improved, the panyl effect of the rubber can be reduced, and the heat generation of the product can be reduced.