The invention provides a sand-fixing and dust-suppressing agent, a sand-fixing and dust-suppressing method and a desert improvement method. The sand-fixing and dust-suppressing agent comprises the following two components: a component A which comprises water glass, starch, a surfactant and water; and a component B which is an acid solution curing neutralizer. According to the sand-fixing and dust-suppressing agent, the sand-fixing and dust-suppressing method and the desert improvement method provided by the invention, the sand-fixing and dust-suppressing agent has characteristics of rapid consolidation, neutrality, temperature resistance and long duration period, and a tough solidified layer can be formed; and the solidified layer can exerts effects of preventing wind erosion, fixing sandand suppressing dust, can maintain underground moisture, also can provide nutrients needed for growth of vegetation, and can improve a desert environment.