The present invention belongs to the technical field of resin composite materials, in particular relates to a low dielectric composite material and a laminate and printed circuit board prepared therefrom. The composite material is obtained by adhering a low dielectric resin composition with phosphorus-containing flame retardant onto a substrate; the composition comprises the following components: (A) phosphorus-containing flame retardant; (B) vinyl compound. The phosphorus-containing flame retardant has a structure as shown in formula (I).In the present invention, diphenylphosphine oxide is derivatized, and prepared a phosphorus-containing flame retardant, which has no reactive functional groups, has better dielectric properties, and has high melting point, and upon combining with a vinyl compound, a resin composition is obtained, and a composite material having low thermal expansion ratio, high heat resistance, high glass transition temperature, and low dielectric constant and dissipation factor, can be made from the resin composition, and a laminate and printed circuit board having the properties of high glass transition temperature, low dielectric properties, halogen-free flame retardancy, low thermal expansion coefficient of the laminate, etc., can be made from the composite material.