How to fix a crack memory card of a cell phone to retrieve pictures

what kind of crack?
did the gold filament crack or just the case? If just the case, try duct-taping it. If the filament, well...can't help you there....

just only the case but i already tried duct- tapping it but it did't open.

well then there must be some damage under the case then. Sorry but i don't know how to retrieve it easily. It will need serious equipment and skill (if any) to retrieve the data if there's damage on the chip.