Provided are a chromium-free surface-treated tinplate, a production method and a surface treating agent thereof. By coating, on the surface of a tinplate, an environmentally friendly aqueous surface treating agent containing 0.1-5 wt % of a zinc salt, 0.1-5 wt % of a zirconium salt and/or a molybdenum salt and 5-30 wt % of siloxane or polysiloxane, a layer of chromium-free passivation film having uniform and dense ingredients and a good performance and being stable is formed on the surface of a tin layer. The passivation film contains 0.1-20 mg/m2 of zinc, 0.1-20 mg/m2 of zirconium and/or molybdenum and 0.5-100 mg/m2 silicon. The passivation film can impart an excellent surface stability, corrosion resistance and paint film adhesion performance to the surface of the tinplate; in addition, contact with food is safe. The tinplate is comparable to chromium passivation in performance, and the production process thereof does not use a chromate, so that a truly green production process of a tinplate is achieved, complying with the requirements of increasingly strict environmental protection laws and regulations.