Floor-penetrating embedded pipe fitting for secondary drainage of modularized integral toilet caisson

The utility model relates to a floor-penetrating embedded pipe fitting for secondary drainage of a modularized integral toilet caisson. The floor-penetrating embedded pipe fitting comprises a main pipe fitting and an expansion part arranged on the outer side wall of the main pipe fitting, a secondary drainage channel is formed in the expansion part, a water inlet of the secondary drainage channel is formed in the upper surface of the expansion part, and a water outlet of the secondary drainage channel is formed in the side wall of the main pipe fitting and communicated with the main pipe fitting. And the secondary drainage channel forms a water seal structure in the expansion part. The through-floor embedded pipe fitting has the beneficial effects that the through-floor embedded pipe fitting can realize secondary water collection and drainage functions of a caisson through the secondary drainage channel in the expansion part, so that the problems of vertical pipe connection and secondary drainage of the caiss