This paper first introduces the basic principle of two kinds of adaptive harmonic current detection models, which are based on adaptive noise cancellation technology (ANCT) and Adaline, respectively. The detection performance, defects and the scope of application of the two models under the condition of the same adaptive algorithm are analyzed, and the impact on the detection performance of different adaptive algorithms with respect to the same model is also provided. Analysis results show that under the conditions of the same algorithm, the convergence rate of the two models is consistent, and the steady state error of the latter is small (theoretical value may be 0) but computationally intensive, the former is only applicable to the case of the high SNR, the detection results of the former is only used as reference signal of the active power filter (APF) while the latter has other applications (e.g., harmonic analysis, protection and control, etc; the impact of different adaptive algorithms on the detection performance of the same model is determined by the algorithm itself. The numerical simulations confirm the validity of the theoretical analysis.