The invention discloses a separate combined type splay saddle and an installation method thereof. The split combination type splay saddle comprises a saddle head and a saddle body which are separated. The bottom of the saddle head is provided with a bottom board, the top of the saddle body is provided with a top board, and a plurality groups of bolt holes corresponding to one another are arranged between the bottom board and the top board. A seam allowance groove is concaved inwards, matched with the bottom board and arranged on the top face of the top board, the saddle head is arranged in the seam allowance groove on the top board of the saddle body in an embedded mode through the bottom board, and the bottom board of the saddle head and the top board of the saddle body are locked tightly and combined together though bolt sets penetrating through the bolt holes corresponding to one another. According to the separate combined type splay saddle, the saddle head and the saddle body matched with each other are formed, therefore, the splay saddle can effectively and reliably achieve easy positioning and installation on the premise that manufacture and transportation are facilitated; the difficulty of alignment and assembling between the saddle head and the saddle body is small, the qualification rate and the accuracy of combination of the saddle head and the saddle body are high, the structural strength is high, the quality is reliable, the practicability is high, and the installation method is particularly suitable for formation of a large-tonnage splay saddle of large-scale suspension bridge engineering.