Oil spill pollution on the sea surface is one of the most common pollutions, which usually exists on the sea surface in different weathering states, such as oil film in the unemulsified stage, oil-in-water and water-in-oil in the emulsified stage. Therefore, rapid and accurate monitoring of oil spill information on the sea surface, and identification, classification and quantitative assessment of oil spill pollution at different stages are of great significance to the rapid control of marine pollution and the restoration of the ecological environment. Laser induced fluorescence (LIF) is currently one of the most effective technologies for remote sensing detection of the sea surfaces. The bidirectional reflectance and reradiation distribution function (BRRDF) characterizes the fluorescence properties of the target by describing the fluorescence distribution of the stimulated emission. At present, the fluorescence characteristics of water-in-oil emulsion in the emulsification stage have not been studied except oil film in the unemulsified stage and oil-in-water in the emulsification stage based on LIF detection technology. Because of this, the optical parameters of water-in-oil emulsion are obtained using the Mie scattering theory. The Monte Carlo photon transmission model of water-in-oil emulsion is established to carry out BRRDF research. The variation of f_BRRDFcosθ_rcosθ_i (the zenith angle of fluorescence emission is θ_r, and the zenith angle of laser incidence is θ_i) of water-in-oil emulsion under the parameters of oil content, incident-receiving angle, and thickness is discussed and analyzed. The experimental data of the fluorescence spectrum are compared with the simulation. The results show that the value of f_BRRDFcosθ_rcosθ_i decreases with the increase of the oil content of the emulsion (the oil content of the surface emulsion of sea-water) and has a consistent trend with the spectral data collected by the experiment, which provides the basis for inferring the oil content of water-in-oil emulsion based on LIF technology. The value of f_BRRDFcosθ_rcosθ_i first stabilizes with the increase of θ_i and decreases rapidly when θ_i>65°, and gradually decreases with the increase of θ_r, which is consistent with the trend of spectral data collected by experiments. This trend indicates that the incident angle of the laser should not exceed 65°, and the maximum optical signal can be received perpendicular to the sea surface when LIF technology is used to detect the water-in-oil emulsion on the sea surface. The value of f_BRRDFcosθ_rcosθ_i rises first and then becomes stable with the increase of emulsion thickness, which indicates that f_BRRDFcosθ_rcosθ_i can be used to evaluate the minimum thickness of water-in-oil emulsion. The research content of this paper provides theoretical and technical support for detecting oil spills on the sea surface based on LIF technology.