With the rapid development of short-range communication and powering in 5G and beyond system, near-field multi-focus array received attention recently as it can offer designated power pattern on multiple target or regions with high efficiency. And the NFMF array is prone to adopt large-scale array to fulfill the focusing requirement for communication and powering, which may suffer failure of array elements for long-term use. Therefore, the studies in robustness of design algorithm against array element failure is proposed and discussed both in theory and experiment, then conclude the stability of NFMF array under various of focusing situations.