This paper investigates collision detection between cylindrical or cylinder-enveloped components when mutual blocking occurs in the view of microscopes and detach control to separate objects if contact occurs. We use a projection method to convert two microscopic views to contours on a projection plane and to detect high-dimensional collision by studying the projection's relationships in low dimension. Eleven cases are totally categorized and 12 parameters are constructed for detection on the basis of relative postures and positions. Furthermore, we present a detach controller to handle with object contact according to collision status, objects' main axis, and the computed contact position. Simulations and experiments are carried out to demonstrate the validity of the proposed method.