In order to improve the spectral efficiency of existing optical spatial modulation systems, an optical generalized quadrature spatial modulation（OGQSM） technology is proposed, in which multiple transmitting optical antennas are simultaneously activated in the in-phase and quadrature domains to transmit the real and imaginary parts of the modulated signals respectively. This technology extends the modulation symbols to the in-phase and quadrature domains, so that the system can carry more bits in the spatial domain, thus improving the spectral efficiency and bit error performance of the system. The Malaga turbulent channel which is suitable for all turbulent states is used to analyze the OGQSM system bit error performance of the proposed technology under the combined action of atmospheric turbulence, pointing error and path loss. Monte Carlo simulation results show that, compared with the existing optical spatial modulation technology, the proposed OGQSM technology can obtain better spectral efficiency and error performance, and the number of receiving optical antennas is positively correlated with the bit error performance of the system, the pointing error and the atmospheric turbulence intensity are negative correlated with the bit error performance of the system.