var template = @"
BEGIN:VCARD
VERSION:2.1
N;CHARSET=gb2312:;{0};;;
FN;CHARSET=gb2312:{0}
TEL;CELL:{1}
EMAIL;WORK:{2}
ADR;WORK;CHARSET=gb2312:;;{3};;;{6};
ORG;CHARSET=gb2312:{4}
TITLE;CHARSET=gb2312:{5}
END:VCARD
";
            StringBuilder sb = new StringBuilder();
            foreach(var item in items)//items可以直接从Excel复制过来
            {
                var i = item.Split('\t');
                sb.AppendFormat(template, "姓名", "1390000", "13@qq.com", "地址", "公司", "职务", "310001");
            }

            File.WriteAllText("电子通讯录.vcf", sb.ToString(),Encoding.Default);

其实没什么好说的，关键点就是gb2312 和 Encoding.Default

[C#] 生成中文电子通讯录