my taxable income is $8,054 ($22,654 - $14,600), why it's 12% tax rate, it is under $11,600. should only subjected 10% and pay $806 instead of $966. Please help.

I suggest you look at your actual 1040tax return.

From the left sidebar

1. Select Tax tools
2. Hint: You may have to minimize the Federal and State selections
3. Click Tools
4. A Menu will pop up
5. Select View tax summary
6. On the left panel click Preview my 1040

Some Key numbers to compare:

• 11 Adjusted Gross Income
• 12 Deductions
• 15 Taxable income
• 16 Tax
• 33 Total Payments
• 34 Overpayment
• 35a Refund
• 37 Amount you owe

I clicked "Tax Tool", and I saw the total income is still the same, $22,654, and deduct the standard deduction $14,600, taxable income is $8,054, so the question is still the same, $8,054 is 10%, why turbo tax use 12%? thank you.  

Did you have any business income.  

1. You would have to pay an additional self employment tax.
2. This would be posted to line 23 of the 1040.
3. Did you look on the actual tax form as described above.