The 3 bands of speaking above are 7, 8 and 9. As you can see, using idioms, even with some inappropriate choices, is typical of a band 7 candidate. By using them skillfully, with only occasional inaccuracies you are likely to get an 8 in this category. Rarely students use them perfectly and this is typical of someone who reaches a 9.
Today, I am going to share you 10 common idioms for IELTS speaking test:
1.make a beeline for 直奔，直冲
Meaning:go rapidly and directly towards.
eg：After I come home from work/study, I always feel exhausted. I just make a beeline for the sofa lying like a dead.
2.Jump (orclimb) on the bandwagon
Meaning: Join others in doing or supporting something fashionable or likely to be successful.
eg:When your TV show does extremely well, advertisers will be competing to be the first to jump on the bandwagon.
eg: Ican'tstandthesepeoplewhojustjumponthe bandwagonafterawin.
3.Off (orway off) beam
Meaning:On the wrong track; mistaken.
eg:I lost the bet/competition as my prediction was way off beam.
4.At someone’s beck and call
Meaning:Always having to be ready to obey someone’s orders immediately.
eg: It should be my sister at my beck and call to drive us to the shopping mall.
5.Pass (orhand) (on) the baton or pick up the baton
Meaning:Hand over a particular duty or responsibility.
If someone passes the baton to another person, they pass responsibility for something to that person. If someone picks up the baton, they take over responsibility for something.
6.Work like a beaver
Meaning:Work steadily and industriously.
eg:She worked like a beaver to empty the house as the new tenant will be moving in tomorrow.
eg: I have to work like a beaver to pass myfinal exam. otherwise, I will be kicked out by the football team.

7.Bed of nails
Meaning:A problematic or uncomfortable situation.
eg: My roommates are very annoying and living with them can be a bed of nails.
8.Beat a (hasty) retreat
Meaning:Withdraw, typically to avoid something unpleasant.
eg: David beat a retreat when he saw his ex-girlfriend walk into the wedding party with another man.
9.Beggar on horseback
Meaning:A formerly poor person made arrogant or corrupt through achieving wealth and luxury.
eg: It’s not surprising that he lost everything and is being investigated by the authorities as he was a beggar on a horseback.
10.A whole new ball game
Meaning:A completely new set of circumstances.
eg: After Sarah joined the Marketing team as General Manager, it was a whole new ball game.