No, the Control Yuan is not a quasi-judicial organization.
Generally speaking, the term of quasi-judicial organization refers to an administrative organization of joint consultation that in addition to its administrative power possesses incomplete judicial power, such as the rental and tenancy mediation committee of a township or a county. By contrast, the Control Yuan is the highest control authority of the nation that exercises the powers of control (supervision) provided by the Constitution and its related laws. It is neither an organization of joint consultation, nor does it possess partial judicial power. In this regard, the Control Yuan is not a quasi-judicial organization.