  Based on the second Gaia data release (DR2) and APOGEE (DR16) spectroscopic
surveys, wedefined two kinds of star sample: high-velocity thick disk (HVTD)
with $v{\phi}>90km/s$ and metal-richstellar halo (MRSH) with $v{\phi}<90km/s$.
Due to high resolution spectra data from APOGEE (DR16),we can analyze
accurately the element abundance distribution of HVTD and MRSH. These
elementsabundance constituted a multidimensional data space, and we introduced
an algorithm method forprocessing multi-dimensional data to give the result of
dimensionality reduction clustering. Accordingto chemical properties analysis,
we derived that some HVTD stars could origin from the thin disk,and some MRSH
stars from dwarf galaxies, but those stars which have similar chemical
abundancecharacteristics in both sample may form in-situ.
