A modular curtain wall and an installing method for the same are provided. The modular curtain wall comprises a steel structure module, a curtain wall module, and a first waterproof member. The steel structure module includes a steel structure body and a mount, and the curtain wall module includes a curtain wall body, a hook, and a first seal. When the hook is hung on the mount, the relative position between the curtain wall body and the steel structure body is adjustable in a front-back direction, the left-right direction, and an up-down direction of the steel structure body.