1, the image processing is improper, the very big picture to take the flash inside to reduce to own need the size, the correct method is you need how big picture on the PS inside processing good, saves in the PNG format.
2, vector map is too complex, such as paper-cut effect. In principle, vector is used, so the file will be a lot smaller, but for the edge is too complex, we would rather use a bitmap will be smaller. Also because of this, so the circle text than Roman text to be larger, in addition to the document scattered than not scattered to small.
3, embed the font, this will make the file much larger. Therefore, when using the input text dynamic text less use uncommon font. Especially Chinese characters, because the number and English words, only need to embed 26 letters and 10 digits on it.
4, the music chooses the WAV format, this is much bigger than the MP3 format.
5, the same element of things as far as possible to convert to components, re-use can not increase the size of the file, but some exceptions, such as your background has a lot of array of circles, let it move the whole, this time to break all the circle than the circle to convert the symbol and then copy is much smaller.
6, need to reuse the animation components, such as you have a bird from left to right, you want to replicate a few, this time the bird animation in the film clips than do in the graphic components in a lot smaller.
7, vector map is converted through the bitmap, such a vector map with too many color points, so that the flash file is very large.
8, bitmap transparent place too much, such as a lot of people like to do the effect of PS text into the flash inside, this will be very large, because the text in many places hollow, transparent place very much. One way to do this is to save the picture as a background, hiding his background with a mask in Flash.
9, import a lot of video files.
10, if you need to use a lot of text, such as Web articles, the proposed device font, font size when using device fonts will show more clearly, and do not occupy file sizes.
Small series for everyone to edit the Flash control swf Size Example tutorial hope to help you!