In this paper,a new direct current (DC) plasma source for surface alloying using array-neodle-cathode has been designed and manufactured.The array-needle-cathode is used to produce a stable abnormal glow discharge plasma in a rectangular chamber..During the surface alloying process,it is noticed that the discharge modes severely influenced the plasma parameters including electron density (Ne) and electron temperature (Te).The Te obtained by optical emission spectrometry (OES) through the comparison of the relative intensity of N(e) in 3919(A) and 3995(A) is between 1.44eV and 5.40eV.The distribution and fluctuation of Te in the two-dimensional planar are revealed by analysis of digital camera images.It is concluded that the discharge by the array-needle-cathode is a kind of new plasma source which can generate stable plasma with a high electron temperature applicable for surface alloying.Lastly,with this array-needle-cathode plasma source (MNDPS),W-Mo-N alloyed layer on Ti alloy is explored in this paper.