Abstract: The hard bearing layer composite pile with rigid core rod-embedded strong mixing soils is composed of the cement-soil mixing piles and the rigid piles. Large diameter formed by low prices of the cement mixing piles makes pile surface area increases, so that the pile friction resistance of the piles increases significantly. It is characterized by convenience, strong applicability, reliable pile quality, fast construction speed, low cost, high bearing capacity, no soil squeezing and without mud outbound processing, etc., and the problem of low side friction of the piles in deep soft soil layer is solved. The force mechanisms of the vertical bearing capacity of composite piles and single pile are highlighted.