The present invention relates to a phosphazene compound and a composite metal laminate. The phosphazene compound with a partial structure of carboxylic esters has a structure as shown in Formula (I). The present invention obtains a phosphazene compound with a partial structure of carboxylic esters using an M group having specific components. The cured products of the phosphazene compound have good flame retardancy, heat resistance, mechanical properties, flame retardancy, and low dielectric constant, and are a low dielectric flame retardant material having great economic properties and being environmental friendly.