The invention discloses a conversion frame assembly sectional material of a side-hung window, and relates to the field of building materials. The conversion frame assembly sectional material of the side-hung window comprises a vertical frame sectional material, a conversion frame sectional material and a line pressing sectional material, wherein the right end of the vertical frame sectional material is connected with the conversion frame sectional material in an assembling mode, and glass is assembled at the right end of the conversion frame sectional material through the line pressing sectional material. The conversion frame sectional material comprises a conversion frame central plate, a right-angle clamping edge is arranged at the left side of the upper end of the conversion frame central plate, a line pressing clamping groove is formed in the right side of the upper end of the conversion frame central plate, an edge sealing clamping plate extending leftwards is arranged at the lower end of the conversion frame central plate, an inclined-angle clamping edge is arranged at the front end of the edge sealing clamping plate, a glass baffle extending rightwards is arranged at the lower end of the conversion frame central plate, and a clamping groove is formed in the front end of the glass baffle. The conversion frame assembly sectional material of the side-hung window is simple in structure, reasonable in design, convenient to construct and install, safe and environmentally friendly to use, high in production efficiency, low in cost, good in sealing performance and small in noise, prevents components from being deformed easily and can be widely applied to aluminum alloy window sashes.