They do not need foreign capital per se. They need foreign business expertise and technology in areas where domestic ones are not sufficient at the moment. For pure capital they have more than enough in US debt, maybe even too much, since they try to allocate as much of it as possible (e.g. using the one belt initiative) without launching RMB exchange rate into space.

With the mounting up US sanctions, trade wars, and "friend-shoring", China will have less and less interest in western investments.