In this paper, the influence of the number of spatial confinement walls on laser-induced Cu plasma spectra was studied in an atmospheric environment. The experiment discovered that the spectral intensity, SBR, and electron temperature of Cu plasma increased with increasing spatial confinement walls; when the confinement cavity was the cylindrical wall, the spectral intensity, SBR, and electron temperature of the plasma were the highest. The spatial confinement effect resulted from the shock wave reflected from the confinement cavity wall compressing the plasma plume. As the number of confinement walls increased, the energy of the shock wave used to confine the plasma continued to grow, and the coupling degree of the shock wave and plasma plume was also increasing, resulting in the continuous enhancement of the compression effect of the plasma. In conclusion, it can be seen that a sufficient number of spatial confinement walls can effectively increase the spectral intensity, SBR, and electron temperature, thereby improving spectral signal and sensitivity.