crontab is not running my script
When you put 1 in the first column, it will run on the first minute (of every hour). In order to get it to run in every minute of every hour, you need to set the minute column as */1
So your line should read:
*/1 * * * * /Users/apple/Desktop/wget/down.sh
supporting links:job every minute: https://bbs.archlinux.org/viewtopic.php?id=59180
job every 5 minutes: http://www.thegeekstuff.com/2011/07/cron-every-5-minutes/
Do you have a typo? It looks like you might have mis-typed Desktop?
Another thing to do is to redirect the output of running the script to a file so you can see what's going on like this:
1 * * * * /Users/apple/Destop/wget/down.sh >> /tmp/cron.out
and then check out the file to see what's going on.