There is a serious multipath effect when the radar measures the target at a low elevation angle. The complex position makes the multipath echo produce irregular reflection, which results in different degrees of amplitude and phase distortion. In this study, a perturbational multipath model is introduced to solve the mismatch between the classical multipath model and the multipath echo reflection of the complex positions, and a height measurement method of the synthesized vector maximum likelihood (SVML) based on the perturbational model is studied. Perturbation parameters are introduced to characterize multipath echo phenomena of complex positions and are obtained by the perturbational multipath sparse Bayesian learning (PSBL) algorithm. The obtained parameters are applied to the SVML algorithm, which improves the height measurement performance of VHF radars in complex positions.