From Refs [1]-[2], your original sentence is in case no. 1 (The participle without comma).
Case 1: Main Clause + Ø + Participle Phrase
We are a Zhongguancun-based English training school looking for native English speakers from the US and Canada.
Note: A participle phrase of "looking for... " will modify the nearest word that should be Noun in the main clause (English training school).
The full meaning of this sentence is as follows:
We are a Zhongguancun-based English training school that looks for native English speakers from the US and Canada.
We can split into 2 separate sentences.
We are a Zhongguancun-based English training school.
And
Then, a Zhongguancun-based English training school looks for native English speakers from the US and Canada.
Case 2: Main Clause + , + Participle Phrase (with comma)
We are a Zhongguancun-based English training school, looking for native English speakers from the US and Canada.
A participle phrase of "looking for... " will modify the Subject in the main clause to describe the conclusion (or result) of the main clause.
This sentence means:
We are a Zhongguancun-based English training school.
And
We look for native English speakers from the US and Canada.
More samples in [2]:
The lake shimmered in the noonday sun, giving me peace.
The meaning of sentence is as follows.
When the lake shimmered in the noonday sun, the lake also give me the peace.
More samples in [6]: It looks like the clause-effect.
My sister finally quit her job, discouraged by the long hours and low pay.
It means:
My sister finally quit her job, because she was discouraged by the long hours and low pay.
My Recommendations
However, I would prefer to delete "We are ...". This is because we are human.
We are a school ...!?
It should be like this.
Zhongguancun-based English training school is looking for native English speakers from ...
Or
We are the members of Zhongguancun-based English training school, looking for native English speakers from ...
References for Participle Phrase
[1] http://www.chompchomp.com/terms/participlephrase.htm
[2] https://writerschoices.files.wordpress.com/2011/11/webpartphr.pdf
[3] https://owl.purdue.edu/owl/general_writing/mechanics/gerunds_participles_and_infinitives/participles.html
[4] http://www.grammar-monster.com/glossary/participle_phrases.htm
[5] http://www.sjsu.edu/writingcenter/handouts/Participle%20Phrases.pdf
[6] https://www.thoughtco.com/what-is-a-participial-phrase-1691588