The invention provides an optical antenna integrating polarization, isolation, receiving and transmitting. A laser beam of a laser emission module passes a wave plate group formed by a lambda/4 wave plate and a second lambda/2 wave plate to become S linearly polarized light. The S linearly polarized light reaches a first lambda/2 wave plate through a polarization beam splitter to be modulated into linearly polarized light, wherein an angle of 45 degrees is formed between the linearly polarized light and the original polarization direction. The linearly polarized light is emitted through a collimating mirror and an optical antenna. During receiving, an incidence light signal received by the optical antenna reaches the first lambda/2 wave plate through the collimating mirror, and is subjected to transmission and modulated into linearly polarized light of P polarization. The linearly polarized light of P polarization is output in a lossless manner through the polarization beam splitter, reaches an optical receiving module through a light gathering mirror and then is received by a detector of the optical receiving module. The optical path of the receiving light output by the polarization beam splitter is perpendicular to the optical path of the emission light entering the polarization beam splitter. The same optical antenna of the receiving end is arranged opposite to the emission end. An angle of 45 degrees is formed between fast axes of the first lambda/2 wave sheets of the receiving end and the emission end. Thus, weight and size of the system are greatly reduced; networking is convenient to perform; reliability is high; receiving signal to noise ratio is improved; and the optical antenna is especially suitable for satellite optical communication.