The invention discloses a sanitary appliance in-pipe fixing and connecting mechanism, which comprises a fixing bolt, a fixing nut, an in-pipe fastener, a clamping spring and an object placing rod, wherein the fixing nut is matched with the fixing bolt, the in-pipe fastener is sheathed at the outer side of the fixing nut, the clamping spring is arranged on the in-pipe fastener, the object placing rod is arranged at the outer side of the in-pipe fastener, the in-pipe fastener comprises two semicircular arc-shaped clamping sheets, the upper end of each clamping sheet is provided with a first protrusion part, the lower end of each clamping sheet is provided with a second protrusion part, an inner concave part is arranged between each first protrusion part and each second protrusion part, the middle of each inner concave part is provided with an inverted hook which is inwards folded, and the lower end of each clamping sheet is provided with a convergent part. The mechanism has the advantages that the defects of existing sanitary appliance fixing device are overcome, the installation steps are simplified, and the condition of looseness of the object placing rod in a washroom after fixing is effectively avoided.