In this paper, doping, electric conductivity, field emission and electrochemical properties of nanocrystalline diamond films are reviewed, which contain n-type nanocrystalline diamond (NCD) films prepared by chemical vapor deposition, improvement of n-type electrical conductivity in NCD films by ion implantation, excellent field emission properties of NCD films prepared by metal ion implantation, high mobility n-type conductivity obtained by low dose ion implantation and oxygen termination on grain surface, regulation of the structure of NCD/graphene and its influence on electrical and electrochemical properties, microstructure and electrochemical regulation of boron-doped NCD film electrodes and so on. It shows through comprehensive analysis that grain doping and surface/interface coordination can improve the electrical properties, field emission properties and electrochemical properties of thin films, which has important application prospects in the fields of diamond-based nano-electronic devices and electrochemical electrodes.