Purpose To observe the characteristics of highly myopic macular holes (HMMHs) with macular retinoschisis (MRS) by optical coherence tomography (OCT) and explore the possible relationship between HMMHs and different types of MRS. Methods We consecutively reviewed the clinical data and OCT images of the patients with HMMHs from June 2015 to February 2021. Then we picked eyes with MRS from these HMMHs for analysis. The minimum linear diameter (MLD), basal diameter (BD), and height (H) of HMMHs were measured. HMMHs were grouped according to the extent or layer involvement of the concomitant MRS and the characteristics were compared among groups. The impact of MRS on the MLD of macular hole was analyzed with multivariable linear regression. Results We included 127 patients with MRS from 168 HMMHs (75.5%) for analysis. According to the different classification systems, the most frequent type of MRS in HMMHs was S3 (foveal but not entire macular area MRS) (62.2%) and both inner- and outer- (I/O-MRS) involved types. In our study, HMMHs with more extensive MRS had larger MLD, larger BD, larger H, and poorer best-corrected visual acuity (BCVA). Meanwhile, HMMHs with outer layer-involved MRS (outer MRS and I/O-MRS) had larger BD than HMMH with only inner layer-involved MRS. (All P < 0.05) Multivariable linear regression further illustrated only the extent of MRS was significantly associated with the MLD of HMMH, while there was no significant correlation between the involved retinal layers and the MLD of HMMH. Conclusion HMMH with MRS presented as a predominant type in HMMHs. The MRS was always with a relatively large extent and involved both inner and outer layers. MLD of HMMH was mainly affected by the extent of MRS.