A single waterway valve core structure comprises a valve housing, a valve cover, a temperature regulating valve rod, a water stop piece, and a hollow water stop pad. A bottom of the valve housing comprises a water inlet cavity, and a side wall of the valve housing comprises a water outlet. The water stop piece is integrally formed on a bottom end of the temperature regulating valve rod, and the bottom end of the temperature regulating valve rod comprises one or more water passing holes. A side wall of the temperature regulating valve rod comprises a side outlet hole in communication with the water outlet. The hollow water stop pad is disposed in the water inlet cavity, the temperature regulating valve rod is disposed in the valve housing, and the water stop piece contacts the hollow water stop pad.