Hi A Wu,
You can claim remittance basis and split year treatment at the same time.
You do not need to claim split year treatment for the income and/or gains, if you are claiming the remittance basis for that same income / gains.
To claim remittance basis and or split year treatment, requires the completion of a Self Assessment Tax return (SA100) and residence (SA109) and any other supplementary pages:
Self Assessment tax return forms
The remittance basis covers income not remitted to the UK in that tax year.
If you remit that income to the UK in a future year, it will be taxable in that future year.