In this paper, the eavesdropping model based on eavesdroppers near legitimate users, and the effect of atmospheric channel correlation on the physical layer security (PLS) of the free-space optical (FSO) link are analyzed. According to the joint probability density function (PDF) and cumulative distribution function (CDF) of Gamma-Gamma (G-G) distribution, a new closed-form expression of interception probability is derived. Numerical results show that the interception probability of the FSO system depends on turbulence intensity, channel correlation and radial displacement attenuation of eavesdroppers.