The invention provides an insecticidal suspending agent containing dinotefuran. The suspending agent is characterized by being prepared from the following components in mass percentage: 1-30% of the dinotefuran, 0.1-35% of a second active component, 3-9% of a wet dispersant, 0.1-0.5% of a de-foaming agent, 1-6% of an anti-freezing agent, 0.1-4% of a thickening agent, 0.1-0.5% of a preservative, 0-2% of a pH (Potential of Hydrogen) adjusting agent, 0-2% of an antioxidant, 0.5-5% of a functional auxiliary agent and the balancing being water, wherein the second active component is one of bifenthrin, imidacloprid, methylamino abamectin benzoate, cyhalothrin, thiamethoxam, indoxacarb, chlorfenapyr, acetamiprid and ethiprole. According to the insecticidal suspending agent, special components are selected and the content of each component is strictly limited; and the prepared insecticidal suspending agent has the very good fast-acting property and lasting period and has the very good prevention effect on tea lesser leafhopper, aleyrodid, thrips, aphids and the like. After the functional auxiliary agent is added, the insecticidal efficacy is improved by 10-12% when being compared with a medicament which is not added with the functional auxiliary agent.