The invention provides a method of manufacturing a water-absorbent resin composition containing water-absorbent resin particles and additive particles, by which it is possible to obtain a water-absorbent resin composition that sufficiently exhibits additional functions, such as an anti-blocking property under moisture absorption, of the additive particles while maintaining an excellent water absorption property. A method of manufacturing a water-absorbent resin composition includes a resin particle preparation step (s1) and a mixing step (s2). In the mixing step (s2), water-absorbent resin particles which are prepared in the resin particle preparation step (s1) are mixed with additive particles in multiple stages by using a plurality of mixing apparatuses to obtain a water-absorbent resin composition.本發明係關於一種製造方法，其係包含吸水性樹脂粒子與添加劑粒子之吸水性樹脂組合物之製造方法，該製造方法可獲得維持優異之吸水特性、且充分發揮耐吸濕黏連性等添加劑粒子所具有之附加功能之吸水性樹脂組合物。吸水性樹脂組合物之製造方法包括樹脂粒子製備步驟(s1)、及混合步驟(s2)。混合步驟(s2)中，使用複數個混合裝置將樹脂粒子製備步驟(s1)中製備之吸水性樹脂粒子與添加劑粒子以多階段進行混合，獲得吸水性樹脂組合物。
