Aspects for active alignment for assembling optical imaging systems are described herein. As an example, the aspects may include aligning an optical detector with an optical component. The optical component is configured to alter a direction of one or more light beams emitted from an image displayed by an optical engine. The aspects may further include detecting, by the optical detector, a virtual image generated by the one or more light beams emitted by the optical engine; and adjusting, by a multi-axis controller, an optical path of the one or more light beams based on one or more parameters of the virtual image collected by the optical detector.