Photon trapping and outflow are two key physics issues associated with supercritical accretion flow. We investigated the conflict between these two processes based on two-dimensional radiation-hydrodynamic (RHD) simulation data, and constructed a simplified (radially) one-dimensional model. Mass loss due to outflow, which is not considered in the slim-disk model, reduces the surface density of the flow, and if very significantly, it can totally suppress the photon-trapping effects. If photon trapping is very significant, conversely, outflow can be suppressed because the radiation-pressure force is reduced. To see what actually occurs, we examined the RHD simulation data and evaluated the accretion and outflow rates as functions of the radius. We have found that the accretion rate monotonically decreases, while the outflow rate increases, as the radius decreases. However, the accretion remains constant at small radii, inside several Schwarzschild radii, since the outflow is suppressed by photon trapping effects. To understand the conflict between the photon trapping and outflow in a simpler way, we modeled the radial distribution of the accretion rate from our simulation data, and built up a new (radially) one-dimensional model, which is similar to the slim-disk model, but incorporates mass loss effects due to the outflow. We find that the surface density (and, hence, the optical depth) is greatly reduced even inside the trapping radius, compared to the case without outflow, whereas the effective temperature distribution hardly changes. That is, the emergent spectra do not sensitively depend on the amount of mass outflow. We conclude that the slim-disk approach is valid for interpreting observations, even if the outflow is taken into account. The observational implications of our findings are briefly discussed in relation to ultra-luminous X-ray sources.