The primary aim of the study is to assess the antihypertensive efficacy of SPH3127 in patients with mild to moderate essential hypertension.

Inclusion Criteria:

1. Male or female of age ≥18 years;
2. Diagnosed with mild-moderate essential hypertension;
3. Participant has understood the study-required procedures, voluntarily signed informed consent.

Exclusion Criteria:

1. Diagnosed with secondary hypertension, suspected grade 3 hypertension, acute hypertension, or at risk when current antihypertensive therapy discontinued;
2. Suffered by severe heart disease within 6 months;
3. Suffered by severe cerebrovascular disease within 6 months;
4. Suffered by severe or malignant retinopathy;
5. Out of controlled diabetes;
6. History of malignant tumor;
7. History of mental disorder;
8. Subject is planning or in use of other antihypertensive drugs or other drugs may affect blood pressure during the trial;
9. Alcohol or drug abuse;
10. Pregnant, lactating women or subject is planning to pregnant within 6 months after the trial;
11. Assessed by the investigators as unsuitable for participating in the study.