An experimental study is performed to control flow separation from a two-dimensional curved ramp using a spanwise pulsed blowing slit jet placed near the separation point of the baseline flow. The momentum-thickness-based Reynolds number $ \textit{Re}_{\theta}$ is 5700. Four control parameters are investigated, including the velocity ratio $\overline{U_{J,c}^{*}}$, duty cycle dc, dimensionless excitation frequency $f_{e}^{{*}}$ and jet blowing angle $\alpha$. The control mechanisms are found to differ from small to large jet angle. Empirical scaling analysis for $\alpha \leq 55^{\circ}$ unveils that $\Delta \overline{C_{p,e}}=f_{1}(\overline{U_{J,c}^{*}}, { d}c, f_{e}^{*}, \alpha , Re_{\theta })$ may be reduced to $\Delta \overline{C_{p,e}}/\varPi (\tau )=f_{2}(\xi )$, where $f_{1}$ and $f_{2}$ are different functions, $\Delta \overline{C_{p,e}}$ is the variation in the pressure coefficient at the end of the ramp under control, $\varPi (\tau )$ is a function of dimensionless duration $\tau$ at which the jet is closed within one excitation period, $\Delta \overline{C_{p,e}}/\varPi (\tau )$ represents the control efficiency, and $\xi$ is a scaling factor that is physically the energy ratio per unit area of the blowing jet to the mainstream. This scaling law is also found to be valid for steady jet control. Several interesting inferences can be made from this scaling law, which provides important insight into the physics of flow separation control.