tinymce的段落间的格式 - gitsnippet/blog GitHub Wiki

From tinyMCE 4.x you can specify this option
forced_root_block_attrs: { “style”: “margin: 5px 0;” }
this will append style: margin: 5px 0; for every p tag.
P.S: it will not work for copy/paste content.
Refer: http://archive.tinymce.com/wiki.php/Configuration:forced_root_block_attrs