@haochun On the first call Aspose.Words inits static resources, which are reused on the next calls. I have tested your code on my side with the latest 21.12 version of Aspose.Words and the result is much better than yours:
0 use :208
1 use :6
2 use :4
3 use :5
4 use :4
5 use :3
6 use :3
7 use :3
8 use :3
9 use :3
@haochun I have tested the scenario once again and it seems you are using Aspose.Words in Evaluation mode. This gives a difference in the first run init time. For example on my PC I get the following results when run Aspose.Words in evaluation mode:
0 use :610
1 use :3
2 use :3
3 use :3
4 use :3
5 use :2
6 use :2
7 use :2
8 use :2
9 use :2
and the following results when run in licensed mode:
0 use :106
1 use :3
2 use :2
3 use :2
4 use :2
5 use :2
6 use :2
7 use :1
8 use :2
9 use :2