在可以调用OLE之前，必须将当前线程设置为单线程单元（STA）模式，请确保您的Main函数带有STAThreadAttribute

        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        private static void Main(String[] args)
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
　　　　　　  Application.Run(new LoginForm());
        }   

　　　　public string importPath=""; //全局变量，用于显示导入文件路劲

        private void btnImport_Click(object sender, EventArgs e)
        {
            Thread importThread = new Thread(new ThreadStart(ImportDialog));
            importThread.SetApartmentState(ApartmentState.STA); //重点
            importThread.Start();
            txtImportPath.Text = importPath;
        }
        public void ImportDialog()
        {
            OpenFileDialog open = new OpenFileDialog();
            open.Filter = "Excel文件|*.xls;*.xlsx";
            if (open.ShowDialog() == DialogResult.OK)
            {
                importPath = open.FileName;

                ReadExcelToTable(importPath);
                UpdateArea();
            }
        }