diff --git a/src/components/BpmnDesign/index.vue b/src/components/BpmnDesign/index.vue
index af1bde2..1568a3e 100644
--- a/src/components/BpmnDesign/index.vue
+++ b/src/components/BpmnDesign/index.vue
@@ -173,13 +173,13 @@ const initDiagram = (xml?: string) => {
  */
 const fitViewport = () => {
   zoom.value = bpmnModeler.value.get<Canvas>('canvas').zoom('fit-viewport');
-  const bbox = (document.querySelector('.app-containers .viewport') as SVGGElement).getBBox();
-  const currentViewBox = bpmnModeler.value.get('canvas').viewbox();
+  const bbox = document.querySelector<SVGGElement>('.app-containers .viewport').getBBox();
+  const currentViewBox = bpmnModeler.value.get<Canvas>('canvas').viewbox();
   const elementMid = {
     x: bbox.x + bbox.width / 2 - 65,
     y: bbox.y + bbox.height / 2
   };
-  bpmnModeler.value.get('canvas').viewbox({
+  bpmnModeler.value.get<Canvas>('canvas').viewbox({
     x: elementMid.x - currentViewBox.width / 2,
     y: elementMid.y - currentViewBox.height / 2,
     width: currentViewBox.width,
@@ -192,9 +192,9 @@ const fitViewport = () => {
  * @param zoomIn true 放大 | false 缩小
  */
 const zoomViewport = (zoomIn = true) => {
-  zoom.value = bpmnModeler.value.get('canvas').zoom();
+  zoom.value = bpmnModeler.value.get<Canvas>('canvas').zoom();
   zoom.value += zoomIn ? 0.1 : -0.1;
-  bpmnModeler.value.get('canvas').zoom(zoom.value);
+  bpmnModeler.value.get<Canvas>('canvas').zoom(zoom.value);
 };
 
 /**