'Preview Formatted Tab' window cannot correctly show formatted text according to the current output style.

I am trying the biblioscap 7.02. However, I found that the text showed in 'the Preview Formatted Tab' window actually cannot be changed by choosing one style as current style in 'Output Style' panel. This may because 'reference type' cannot be changed in 'Output Style' panel.

choosing one style as current style

Hello,
I am not sure what you mean by "'Output Style' panel".
If you mean the panel in which the output styles can be editited, yes, you can't change the current style in this panel. (Or did I overlook something?)
Instead, right-click on the toolbar and switch on the "advanced" toolbar. There you have a dropdown control showing the current output style. You can switch the current style from this control. The 'Preview Formatted Tab' window is updated - at least it works on my system.
- Paul: Is it really the case that one can switch the current output style only by this toolbar control and there is no menu command for doing this?

It does work,thanks!But now

It does work,thanks!
But now I still wonder why the 'Reference type' in "'Output Style' panel" cannot be changed. For example,I click on the 'edit' button(in the right window) and switch the style to 'journal', but when I click the syle again in the left window after I click another one . The 'Reference type' in the right window does not changed in expectation, still being the type of 'book'.

editing output style

The 'Output Style' panel is only for modifying the output style, not for modifying the reference record. The output style contains formatting definitions for the reference types shown in the right column of the 'Output Style' panel. Selecting a reference type in this column just selects it for modification ("edit" button), nothing more.
Not each reference type in the references database needs to have a reference type in the output style. If a reference is to be formatted which is not contained in the output style, Biblioscape can use the "Generic" type for formatting (see Tools - Options - Format Manuscript).
Hope this helps.