about the archive(tag) page

there is a problem on archive page:
https://farm3.static.flickr.com/2446/3958798258_47f14c1b43.jpg

or look at my site：
category page：https://www.gengtang.net/category/wordpress

tag page:https://www.gengtang.net/tag/wordpress

as you see in the picture,the posts per page are 10,but only one tag page is showed(actual posts are 10 over)。 now i want the navigation of tag page to work like the navigation of category page as above in the picture,what shloud i do?

this is the code of controlling the navigation below:

function fvcity_pagenavi($before = '', $after = '', $prelabel = '', $nxtlabel = '', $pages_to_show = 4, $always_show = false) {
	global $request, $posts_per_page, $wpdb, $paged;
	if(empty($prelabel)) {
		$prelabel  = '«';
	}
	if(empty($nxtlabel)) {
		$nxtlabel = '»';
	}
	$half_pages_to_show = round($pages_to_show/2);
	if (!is_single()) {
		if(!is_category()) {
			preg_match('#FROM\s(.*)\sORDER BY#siU', $request, $matches);
		} else {
			preg_match('#FROM\s(.*)\sGROUP BY#siU', $request, $matches);
		}
		$fromwhere = $matches[1];
		$numposts = $wpdb->get_var("SELECT COUNT(DISTINCT ID) FROM $fromwhere");
		$max_page = ceil($numposts /$posts_per_page);
		if(empty($paged)) {
			$paged = 1;
		}
		if($max_page > 0 || $always_show) {
			echo "$before <span class=\"fvpage\">页面 ($max_page):</span> <strong>";
			if ($paged >= ($pages_to_show-1)) {
				echo '<a href="'.get_pagenum_link().'">&laquo; 首页</a> <span class="\fvpage\">...</span> ';
			}
			previous_posts_link($prelabel);
			for($i = $paged - $half_pages_to_show; $i  <= $paged + $half_pages_to_show; $i++) {
				if ($i >= 1 && $i <= $max_page) {
					if($i == $paged) {
						echo "<span class=\"fvpage\">$i</span>";
					} else {
						echo ' <a href="'.get_pagenum_link($i).'">'.$i.'</a> ';
					}
				}
			}
			next_posts_link($nxtlabel, $max_page);
			if (($paged+$half_pages_to_show) < ($max_page)) {
				echo ' <span class="fvpage">...</span> <a href="'.get_pagenum_link($max_page).'">尾页 &raquo;</a>';
			}
			echo "</strong>$after";
		}
	}
}