Abstract: Abstract: This paper， taking HangJiaHuShao metropolitan area as an example， through the construction of structural equation model， analysis the path and mechanism of financial cooperation in metropolitan area. It demonstrates that the economic development is the foundation of metropolitan financial cooperation， and influences financial cooperation through financial development and social security in different ways. Financial development mainly produces polarization effects to financial cooperation， and social security diffusion effect. Thus， overall plans are needed to take both effects into consideration. We should promote financial development as well as raise the level of social security to build a better financial cooperation platform and play the positive effect in metropolitan cities.